DROP TABLE IF EXISTS t0,t1,t2,t3,t4,t5;
DROP VIEW IF EXISTS v1;
show variables where variable_name like "skip_show_database";
Variable_name	Value
skip_show_database	OFF
grant select, update, execute on test.* to mysqltest_2@localhost;
grant select, update on test.* to mysqltest_1@localhost;
create user mysqltest_3@localhost;
create user mysqltest_3;
select * from information_schema.SCHEMATA where schema_name > 'm';
CATALOG_NAME	SCHEMA_NAME	DEFAULT_CHARACTER_SET_NAME	DEFAULT_COLLATION_NAME	SQL_PATH
NULL	mysql	latin1	latin1_swedish_ci	NULL
NULL	test	latin1	latin1_swedish_ci	NULL
select schema_name from information_schema.schemata;
schema_name
information_schema
mysql
test
show databases like 't%';
Database (t%)
test
show databases;
Database
information_schema
mysql
test
show databases where `database` = 't%';
Database
create database mysqltest;
create table mysqltest.t1(a int, b VARCHAR(30), KEY string_data (b));
create table test.t2(a int);
create table t3(a int, KEY a_data (a));
create table mysqltest.t4(a int);
create table t5 (id int auto_increment primary key);
insert into t5 values (10);
create view v1 (c) as select table_name from information_schema.TABLES where table_name<>'ndb_binlog_index' AND table_name<>'ndb_apply_status';
select * from v1;
c
CHARACTER_SETS
COLLATIONS
COLLATION_CHARACTER_SET_APPLICABILITY
COLUMNS
COLUMN_PRIVILEGES
ENGINES
EVENTS
FILES
GLOBAL_STATUS
GLOBAL_VARIABLES
KEY_COLUMN_USAGE
PARTITIONS
PLUGINS
PROCESSLIST
REFERENTIAL_CONSTRAINTS
ROUTINES
SCHEMATA
SCHEMA_PRIVILEGES
SESSION_STATUS
SESSION_VARIABLES
STATISTICS
TABLES
TABLE_CONSTRAINTS
TABLE_PRIVILEGES
TRIGGERS
USER_PRIVILEGES
VIEWS
columns_priv
db
event
func
general_log
help_category
help_keyword
help_relation
help_topic
host
plugin
proc
procs_priv
servers
slow_log
tables_priv
time_zone
time_zone_leap_second
time_zone_name
time_zone_transition
time_zone_transition_type
user
t1
t4
t2
t3
t5
v1
select c,table_name from v1 
inner join information_schema.TABLES v2 on (v1.c=v2.table_name)
where v1.c like "t%";
c	table_name
TABLES	TABLES
TABLE_CONSTRAINTS	TABLE_CONSTRAINTS
TABLE_PRIVILEGES	TABLE_PRIVILEGES
TRIGGERS	TRIGGERS
tables_priv	tables_priv
time_zone	time_zone
time_zone_leap_second	time_zone_leap_second
time_zone_name	time_zone_name
time_zone_transition	time_zone_transition
time_zone_transition_type	time_zone_transition_type
t1	t1
t4	t4
t2	t2
t3	t3
t5	t5
select c,table_name from v1 
left join information_schema.TABLES v2 on (v1.c=v2.table_name)
where v1.c like "t%";
c	table_name
TABLES	TABLES
TABLE_CONSTRAINTS	TABLE_CONSTRAINTS
TABLE_PRIVILEGES	TABLE_PRIVILEGES
TRIGGERS	TRIGGERS
tables_priv	tables_priv
time_zone	time_zone
time_zone_leap_second	time_zone_leap_second
time_zone_name	time_zone_name
time_zone_transition	time_zone_transition
time_zone_transition_type	time_zone_transition_type
t1	t1
t4	t4
t2	t2
t3	t3
t5	t5
select c, v2.table_name from v1
right join information_schema.TABLES v2 on (v1.c=v2.table_name)
where v1.c like "t%";
c	table_name
TABLES	TABLES
TABLE_CONSTRAINTS	TABLE_CONSTRAINTS
TABLE_PRIVILEGES	TABLE_PRIVILEGES
TRIGGERS	TRIGGERS
tables_priv	tables_priv
time_zone	time_zone
time_zone_leap_second	time_zone_leap_second
time_zone_name	time_zone_name
time_zone_transition	time_zone_transition
time_zone_transition_type	time_zone_transition_type
t1	t1
t4	t4
t2	t2
t3	t3
t5	t5
select table_name from information_schema.TABLES
where table_schema = "mysqltest" and table_name like "t%";
table_name
t1
t4
select * from information_schema.STATISTICS where TABLE_SCHEMA = "mysqltest";
TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	NON_UNIQUE	INDEX_SCHEMA	INDEX_NAME	SEQ_IN_INDEX	COLUMN_NAME	COLLATION	CARDINALITY	SUB_PART	PACKED	NULLABLE	INDEX_TYPE	COMMENT
NULL	mysqltest	t1	1	mysqltest	string_data	1	b	A	NULL	NULL	NULL	YES	BTREE	
show keys from t3 where Key_name = "a_data";
Table	Non_unique	Key_name	Seq_in_index	Column_name	Collation	Cardinality	Sub_part	Packed	Null	Index_type	Comment
t3	1	a_data	1	a	A	NULL	NULL	NULL	YES	BTREE	
show tables like 't%';
Tables_in_test (t%)
t2
t3
t5
show table status;
Name	Engine	Version	Row_format	Rows	Avg_row_length	Data_length	Max_data_length	Index_length	Data_free	Auto_increment	Create_time	Update_time	Check_time	Collation	Checksum	Create_options	Comment
t2	MyISAM	10	Fixed	0	0	0	#	1024	0	NULL	#	#	NULL	latin1_swedish_ci	NULL		
t3	MyISAM	10	Fixed	0	0	0	#	1024	0	NULL	#	#	NULL	latin1_swedish_ci	NULL		
t5	MyISAM	10	Fixed	1	7	7	#	2048	0	11	#	#	NULL	latin1_swedish_ci	NULL		
v1	NULL	NULL	NULL	NULL	NULL	NULL	#	NULL	NULL	NULL	#	#	NULL	NULL	NULL	NULL	VIEW
show full columns from t3 like "a%";
Field	Type	Collation	Null	Key	Default	Extra	Privileges	Comment
a	int(11)	NULL	YES	MUL	NULL		select,insert,update,references	
show full columns from mysql.db like "Insert%";
Field	Type	Collation	Null	Key	Default	Extra	Privileges	Comment
Insert_priv	enum('N','Y')	utf8_general_ci	NO		N		select,insert,update,references	
show full columns from v1;
Field	Type	Collation	Null	Key	Default	Extra	Privileges	Comment
c	varchar(64)	utf8_general_ci	NO				select,insert,update,references	
select * from information_schema.COLUMNS where table_name="t1"
and column_name= "a";
TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	COLUMN_NAME	ORDINAL_POSITION	COLUMN_DEFAULT	IS_NULLABLE	DATA_TYPE	CHARACTER_MAXIMUM_LENGTH	CHARACTER_OCTET_LENGTH	NUMERIC_PRECISION	NUMERIC_SCALE	CHARACTER_SET_NAME	COLLATION_NAME	COLUMN_TYPE	COLUMN_KEY	EXTRA	PRIVILEGES	COLUMN_COMMENT
NULL	mysqltest	t1	a	1	NULL	YES	int	NULL	NULL	10	0	NULL	NULL	int(11)			select,insert,update,references	
show columns from mysqltest.t1 where field like "%a%";
Field	Type	Null	Key	Default	Extra
a	int(11)	YES		NULL	
create view mysqltest.v1 (c) as select a from mysqltest.t1;
grant select (a) on mysqltest.t1 to mysqltest_2@localhost;
grant select on mysqltest.v1 to mysqltest_3;
select table_name, column_name, privileges from information_schema.columns 
where table_schema = 'mysqltest' and table_name = 't1';
table_name	column_name	privileges
t1	a	select
show columns from mysqltest.t1;
Field	Type	Null	Key	Default	Extra
a	int(11)	YES		NULL	
select table_name, column_name, privileges from information_schema.columns
where table_schema = 'mysqltest' and table_name = 'v1';
table_name	column_name	privileges
v1	c	select
explain select * from v1;
ERROR HY000: EXPLAIN/SHOW can not be issued; lacking privileges for underlying table
drop view v1, mysqltest.v1;
drop tables mysqltest.t4, mysqltest.t1, t2, t3, t5;
drop database mysqltest;
select * from information_schema.CHARACTER_SETS
where CHARACTER_SET_NAME like 'latin1%';
CHARACTER_SET_NAME	DEFAULT_COLLATE_NAME	DESCRIPTION	MAXLEN
latin1	latin1_swedish_ci	cp1252 West European	1
SHOW CHARACTER SET LIKE 'latin1%';
Charset	Description	Default collation	Maxlen
latin1	cp1252 West European	latin1_swedish_ci	1
SHOW CHARACTER SET WHERE charset like 'latin1%';
Charset	Description	Default collation	Maxlen
latin1	cp1252 West European	latin1_swedish_ci	1
select * from information_schema.COLLATIONS
where COLLATION_NAME like 'latin1%';
COLLATION_NAME	CHARACTER_SET_NAME	ID	IS_DEFAULT	IS_COMPILED	SORTLEN
latin1_german1_ci	latin1	5		#	1
latin1_swedish_ci	latin1	8	Yes	#	1
latin1_danish_ci	latin1	15		#	1
latin1_german2_ci	latin1	31		#	2
latin1_bin	latin1	47		#	1
latin1_general_ci	latin1	48		#	1
latin1_general_cs	latin1	49		#	1
latin1_spanish_ci	latin1	94		#	1
SHOW COLLATION LIKE 'latin1%';
Collation	Charset	Id	Default	Compiled	Sortlen
latin1_german1_ci	latin1	5		#	1
latin1_swedish_ci	latin1	8	Yes	#	1
latin1_danish_ci	latin1	15		#	1
latin1_german2_ci	latin1	31		#	2
latin1_bin	latin1	47		#	1
latin1_general_ci	latin1	48		#	1
latin1_general_cs	latin1	49		#	1
latin1_spanish_ci	latin1	94		#	1
SHOW COLLATION WHERE collation like 'latin1%';
Collation	Charset	Id	Default	Compiled	Sortlen
latin1_german1_ci	latin1	5		#	1
latin1_swedish_ci	latin1	8	Yes	#	1
latin1_danish_ci	latin1	15		#	1
latin1_german2_ci	latin1	31		#	2
latin1_bin	latin1	47		#	1
latin1_general_ci	latin1	48		#	1
latin1_general_cs	latin1	49		#	1
latin1_spanish_ci	latin1	94		#	1
select * from information_schema.COLLATION_CHARACTER_SET_APPLICABILITY
where COLLATION_NAME like 'latin1%';
COLLATION_NAME	CHARACTER_SET_NAME
latin1_german1_ci	latin1
latin1_swedish_ci	latin1
latin1_danish_ci	latin1
latin1_german2_ci	latin1
latin1_bin	latin1
latin1_general_ci	latin1
latin1_general_cs	latin1
latin1_spanish_ci	latin1
drop procedure if exists sel2;
drop function if exists sub1;
drop function if exists sub2;
create function sub1(i int) returns int
return i+1;
create procedure sel2()
begin
select * from t1;
select * from t2;
end|
select parameter_style, sql_data_access, dtd_identifier 
from information_schema.routines;
parameter_style	sql_data_access	dtd_identifier
SQL	CONTAINS SQL	NULL
SQL	CONTAINS SQL	int(11)
show procedure status;
Db	Name	Type	Definer	Modified	Created	Security_type	Comment	character_set_client	collation_connection	Database Collation
test	sel2	PROCEDURE	root@localhost	#	#	DEFINER		latin1	latin1_swedish_ci	latin1_swedish_ci
show function status;
Db	Name	Type	Definer	Modified	Created	Security_type	Comment	character_set_client	collation_connection	Database Collation
test	sub1	FUNCTION	root@localhost	#	#	DEFINER		latin1	latin1_swedish_ci	latin1_swedish_ci
select a.ROUTINE_NAME from information_schema.ROUTINES a,
information_schema.SCHEMATA b where
a.ROUTINE_SCHEMA = b.SCHEMA_NAME;
ROUTINE_NAME
sel2
sub1
explain select a.ROUTINE_NAME from information_schema.ROUTINES a,
information_schema.SCHEMATA b where
a.ROUTINE_SCHEMA = b.SCHEMA_NAME;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	#	ALL	NULL	NULL	NULL	NULL	NULL	
1	SIMPLE	#	ALL	NULL	NULL	NULL	NULL	NULL	Using where; Using join buffer
select a.ROUTINE_NAME, b.name from information_schema.ROUTINES a,
mysql.proc b where a.ROUTINE_NAME = convert(b.name using utf8) order by 1;
ROUTINE_NAME	name
sel2	sel2
sub1	sub1
select count(*) from information_schema.ROUTINES;
count(*)
2
create view v1 as select routine_schema, routine_name from information_schema.routines 
order by routine_schema, routine_name;
select * from v1;
routine_schema	routine_name
test	sel2
test	sub1
drop view v1;
select ROUTINE_NAME, ROUTINE_DEFINITION from information_schema.ROUTINES;
ROUTINE_NAME	ROUTINE_DEFINITION
show create function sub1;
ERROR 42000: FUNCTION sub1 does not exist
select ROUTINE_NAME, ROUTINE_DEFINITION from information_schema.ROUTINES;
ROUTINE_NAME	ROUTINE_DEFINITION
sel2	NULL
sub1	NULL
grant all privileges on test.* to mysqltest_1@localhost;
select ROUTINE_NAME, ROUTINE_DEFINITION from information_schema.ROUTINES;
ROUTINE_NAME	ROUTINE_DEFINITION
sel2	NULL
sub1	NULL
create function sub2(i int) returns int
return i+1;
select ROUTINE_NAME, ROUTINE_DEFINITION from information_schema.ROUTINES;
ROUTINE_NAME	ROUTINE_DEFINITION
sel2	NULL
sub1	NULL
sub2	return i+1
show create procedure sel2;
Procedure	sql_mode	Create Procedure	character_set_client	collation_connection	Database Collation
sel2		NULL	latin1	latin1_swedish_ci	latin1_swedish_ci
show create function sub1;
Function	sql_mode	Create Function	character_set_client	collation_connection	Database Collation
sub1		NULL	latin1	latin1_swedish_ci	latin1_swedish_ci
show create function sub2;
Function	sql_mode	Create Function	character_set_client	collation_connection	Database Collation
sub2		CREATE DEFINER=`mysqltest_1`@`localhost` FUNCTION `sub2`(i int) RETURNS int(11)
return i+1	latin1	latin1_swedish_ci	latin1_swedish_ci
show function status like "sub2";
Db	Name	Type	Definer	Modified	Created	Security_type	Comment	character_set_client	collation_connection	Database Collation
test	sub2	FUNCTION	mysqltest_1@localhost	#	#	DEFINER		latin1	latin1_swedish_ci	latin1_swedish_ci
drop function sub2;
show create procedure sel2;
Procedure	sql_mode	Create Procedure	character_set_client	collation_connection	Database Collation
sel2		CREATE DEFINER=`root`@`localhost` PROCEDURE `sel2`()
begin
select * from t1;
select * from t2;
end	latin1	latin1_swedish_ci	latin1_swedish_ci
create view v0 (c) as select schema_name from information_schema.schemata;
select * from v0;
c
information_schema
mysql
test
explain select * from v0;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	#	ALL	NULL	NULL	NULL	NULL	NULL	
create view v1 (c) as select table_name from information_schema.tables
where table_name="v1";
select * from v1;
c
v1
create view v2 (c) as select column_name from information_schema.columns
where table_name="v2";
select * from v2;
c
c
create view v3 (c) as select CHARACTER_SET_NAME from information_schema.character_sets
where CHARACTER_SET_NAME like "latin1%";
select * from v3;
c
latin1
create view v4 (c) as select COLLATION_NAME from information_schema.collations
where COLLATION_NAME like "latin1%";
select * from v4;
c
latin1_german1_ci
latin1_swedish_ci
latin1_danish_ci
latin1_german2_ci
latin1_bin
latin1_general_ci
latin1_general_cs
latin1_spanish_ci
show keys from v4;
Table	Non_unique	Key_name	Seq_in_index	Column_name	Collation	Cardinality	Sub_part	Packed	Null	Index_type	Comment
select * from information_schema.views where TABLE_NAME like "v%";
TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	VIEW_DEFINITION	CHECK_OPTION	IS_UPDATABLE	DEFINER	SECURITY_TYPE	CHARACTER_SET_CLIENT	COLLATION_CONNECTION
NULL	test	v0	select schema_name from information_schema.schemata	NONE	NO	root@localhost	DEFINER	latin1	latin1_swedish_ci
NULL	test	v1	select table_name from information_schema.tables
where table_name="v1"	NONE	NO	root@localhost	DEFINER	latin1	latin1_swedish_ci
NULL	test	v2	select column_name from information_schema.columns
where table_name="v2"	NONE	NO	root@localhost	DEFINER	latin1	latin1_swedish_ci
NULL	test	v3	select CHARACTER_SET_NAME from information_schema.character_sets
where CHARACTER_SET_NAME like "latin1%"	NONE	NO	root@localhost	DEFINER	latin1	latin1_swedish_ci
NULL	test	v4	select COLLATION_NAME from information_schema.collations
where COLLATION_NAME like "latin1%"	NONE	NO	root@localhost	DEFINER	latin1	latin1_swedish_ci
drop view v0, v1, v2, v3, v4;
create table t1 (a int);
grant select,update,insert on t1 to mysqltest_1@localhost;
grant select (a), update (a),insert(a), references(a) on t1 to mysqltest_1@localhost;
grant all on test.* to mysqltest_1@localhost with grant option;
select * from information_schema.USER_PRIVILEGES where grantee like '%mysqltest_1%';
GRANTEE	TABLE_CATALOG	PRIVILEGE_TYPE	IS_GRANTABLE
'mysqltest_1'@'localhost'	NULL	USAGE	NO
select * from information_schema.SCHEMA_PRIVILEGES where grantee like '%mysqltest_1%';
GRANTEE	TABLE_CATALOG	TABLE_SCHEMA	PRIVILEGE_TYPE	IS_GRANTABLE
'mysqltest_1'@'localhost'	NULL	test	SELECT	YES
'mysqltest_1'@'localhost'	NULL	test	INSERT	YES
'mysqltest_1'@'localhost'	NULL	test	UPDATE	YES
'mysqltest_1'@'localhost'	NULL	test	DELETE	YES
'mysqltest_1'@'localhost'	NULL	test	CREATE	YES
'mysqltest_1'@'localhost'	NULL	test	DROP	YES
'mysqltest_1'@'localhost'	NULL	test	REFERENCES	YES
'mysqltest_1'@'localhost'	NULL	test	INDEX	YES
'mysqltest_1'@'localhost'	NULL	test	ALTER	YES
'mysqltest_1'@'localhost'	NULL	test	CREATE TEMPORARY TABLES	YES
'mysqltest_1'@'localhost'	NULL	test	LOCK TABLES	YES
'mysqltest_1'@'localhost'	NULL	test	EXECUTE	YES
'mysqltest_1'@'localhost'	NULL	test	CREATE VIEW	YES
'mysqltest_1'@'localhost'	NULL	test	SHOW VIEW	YES
'mysqltest_1'@'localhost'	NULL	test	CREATE ROUTINE	YES
'mysqltest_1'@'localhost'	NULL	test	ALTER ROUTINE	YES
'mysqltest_1'@'localhost'	NULL	test	EVENT	YES
'mysqltest_1'@'localhost'	NULL	test	TRIGGER	YES
select * from information_schema.TABLE_PRIVILEGES where grantee like '%mysqltest_1%';
GRANTEE	TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	PRIVILEGE_TYPE	IS_GRANTABLE
'mysqltest_1'@'localhost'	NULL	test	t1	SELECT	NO
'mysqltest_1'@'localhost'	NULL	test	t1	INSERT	NO
'mysqltest_1'@'localhost'	NULL	test	t1	UPDATE	NO
select * from information_schema.COLUMN_PRIVILEGES where grantee like '%mysqltest_1%';
GRANTEE	TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	COLUMN_NAME	PRIVILEGE_TYPE	IS_GRANTABLE
'mysqltest_1'@'localhost'	NULL	test	t1	a	SELECT	NO
'mysqltest_1'@'localhost'	NULL	test	t1	a	INSERT	NO
'mysqltest_1'@'localhost'	NULL	test	t1	a	UPDATE	NO
'mysqltest_1'@'localhost'	NULL	test	t1	a	REFERENCES	NO
delete from mysql.user where user like 'mysqltest%';
delete from mysql.db where user like 'mysqltest%';
delete from mysql.tables_priv where user like 'mysqltest%';
delete from mysql.columns_priv where user like 'mysqltest%';
flush privileges;
drop table t1;
create table t1 (a int null, primary key(a));
alter table t1 add constraint constraint_1 unique (a);
alter table t1 add constraint unique key_1(a);
alter table t1 add constraint constraint_2 unique key_2(a);
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `a` int(11) NOT NULL DEFAULT '0',
  PRIMARY KEY (`a`),
  UNIQUE KEY `constraint_1` (`a`),
  UNIQUE KEY `key_1` (`a`),
  UNIQUE KEY `key_2` (`a`)
) ENGINE=MyISAM DEFAULT CHARSET=latin1
select * from information_schema.TABLE_CONSTRAINTS where
TABLE_SCHEMA= "test";
CONSTRAINT_CATALOG	CONSTRAINT_SCHEMA	CONSTRAINT_NAME	TABLE_SCHEMA	TABLE_NAME	CONSTRAINT_TYPE
NULL	test	PRIMARY	test	t1	PRIMARY KEY
NULL	test	constraint_1	test	t1	UNIQUE
NULL	test	key_1	test	t1	UNIQUE
NULL	test	key_2	test	t1	UNIQUE
select * from information_schema.KEY_COLUMN_USAGE where
TABLE_SCHEMA= "test";
CONSTRAINT_CATALOG	CONSTRAINT_SCHEMA	CONSTRAINT_NAME	TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	COLUMN_NAME	ORDINAL_POSITION	POSITION_IN_UNIQUE_CONSTRAINT	REFERENCED_TABLE_SCHEMA	REFERENCED_TABLE_NAME	REFERENCED_COLUMN_NAME
NULL	test	PRIMARY	NULL	test	t1	a	1	NULL	NULL	NULL	NULL
NULL	test	constraint_1	NULL	test	t1	a	1	NULL	NULL	NULL	NULL
NULL	test	key_1	NULL	test	t1	a	1	NULL	NULL	NULL	NULL
NULL	test	key_2	NULL	test	t1	a	1	NULL	NULL	NULL	NULL
select table_name from information_schema.TABLES where table_schema like "test%";
table_name
t1
select table_name,column_name from information_schema.COLUMNS where table_schema like "test%";
table_name	column_name
t1	a
select ROUTINE_NAME from information_schema.ROUTINES;
ROUTINE_NAME
sel2
sub1
delete from mysql.user where user='mysqltest_1';
drop table t1;
drop procedure sel2;
drop function sub1;
create table t1(a int);
create view v1 (c) as select a from t1 with check option;
create view v2 (c) as select a from t1 WITH LOCAL CHECK OPTION;
create view v3 (c) as select a from t1 WITH CASCADED CHECK OPTION;
select * from information_schema.views;
TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	VIEW_DEFINITION	CHECK_OPTION	IS_UPDATABLE	DEFINER	SECURITY_TYPE	CHARACTER_SET_CLIENT	COLLATION_CONNECTION
NULL	test	v1	select a from t1 with check option	CASCADED	YES	root@localhost	DEFINER	latin1	latin1_swedish_ci
NULL	test	v2	select a from t1 WITH LOCAL CHECK OPTION	LOCAL	YES	root@localhost	DEFINER	latin1	latin1_swedish_ci
NULL	test	v3	select a from t1 WITH CASCADED CHECK OPTION	CASCADED	YES	root@localhost	DEFINER	latin1	latin1_swedish_ci
grant select (a) on test.t1 to joe@localhost with grant option;
select * from INFORMATION_SCHEMA.COLUMN_PRIVILEGES;
GRANTEE	TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	COLUMN_NAME	PRIVILEGE_TYPE	IS_GRANTABLE
'joe'@'localhost'	NULL	test	t1	a	SELECT	YES
select * from INFORMATION_SCHEMA.TABLE_PRIVILEGES;
GRANTEE	TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	PRIVILEGE_TYPE	IS_GRANTABLE
drop view v1, v2, v3;
drop table t1;
delete from mysql.user where user='joe';
delete from mysql.db where user='joe';
delete from mysql.tables_priv where user='joe';
delete from mysql.columns_priv where user='joe';
flush privileges;
create table t1 (a int not null auto_increment,b int, primary key (a));
insert into t1 values (1,1),(NULL,3),(NULL,4);
select AUTO_INCREMENT from information_schema.tables where table_name = 't1';
AUTO_INCREMENT
4
drop table t1;
create table t1 (s1 int);
insert into t1 values (0),(9),(0);
select s1 from t1 where s1 in (select version from
information_schema.tables) union select version from
information_schema.tables;
s1
10
drop table t1;
SHOW CREATE TABLE INFORMATION_SCHEMA.character_sets;
Table	Create Table
CHARACTER_SETS	CREATE TEMPORARY TABLE `CHARACTER_SETS` (
  `CHARACTER_SET_NAME` varchar(64) NOT NULL DEFAULT '',
  `DEFAULT_COLLATE_NAME` varchar(64) NOT NULL DEFAULT '',
  `DESCRIPTION` varchar(60) NOT NULL DEFAULT '',
  `MAXLEN` bigint(3) NOT NULL DEFAULT '0'
) ENGINE=MEMORY DEFAULT CHARSET=utf8
set names latin2;
SHOW CREATE TABLE INFORMATION_SCHEMA.character_sets;
Table	Create Table
CHARACTER_SETS	CREATE TEMPORARY TABLE `CHARACTER_SETS` (
  `CHARACTER_SET_NAME` varchar(64) NOT NULL DEFAULT '',
  `DEFAULT_COLLATE_NAME` varchar(64) NOT NULL DEFAULT '',
  `DESCRIPTION` varchar(60) NOT NULL DEFAULT '',
  `MAXLEN` bigint(3) NOT NULL DEFAULT '0'
) ENGINE=MEMORY DEFAULT CHARSET=utf8
set names latin1;
create table t1 select * from information_schema.CHARACTER_SETS
where CHARACTER_SET_NAME like "latin1";
select * from t1;
CHARACTER_SET_NAME	DEFAULT_COLLATE_NAME	DESCRIPTION	MAXLEN
latin1	latin1_swedish_ci	cp1252 West European	1
alter table t1 default character set utf8;
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `CHARACTER_SET_NAME` varchar(64) NOT NULL DEFAULT '',
  `DEFAULT_COLLATE_NAME` varchar(64) NOT NULL DEFAULT '',
  `DESCRIPTION` varchar(60) NOT NULL DEFAULT '',
  `MAXLEN` bigint(3) NOT NULL DEFAULT '0'
) ENGINE=MyISAM DEFAULT CHARSET=utf8
drop table t1;
create view v1 as select * from information_schema.TABLES;
drop view v1;
create table t1(a NUMERIC(5,3), b NUMERIC(5,1), c float(5,2),
d NUMERIC(6,4), e float, f DECIMAL(6,3), g int(11), h DOUBLE(10,3),
i DOUBLE);
select COLUMN_NAME,COLUMN_TYPE, CHARACTER_MAXIMUM_LENGTH, 
CHARACTER_OCTET_LENGTH, NUMERIC_PRECISION, NUMERIC_SCALE
from information_schema.columns where table_name= 't1';
COLUMN_NAME	COLUMN_TYPE	CHARACTER_MAXIMUM_LENGTH	CHARACTER_OCTET_LENGTH	NUMERIC_PRECISION	NUMERIC_SCALE
a	decimal(5,3)	NULL	NULL	5	3
b	decimal(5,1)	NULL	NULL	5	1
c	float(5,2)	NULL	NULL	5	2
d	decimal(6,4)	NULL	NULL	6	4
e	float	NULL	NULL	12	NULL
f	decimal(6,3)	NULL	NULL	6	3
g	int(11)	NULL	NULL	10	0
h	double(10,3)	NULL	NULL	10	3
i	double	NULL	NULL	22	NULL
drop table t1;
create table t115 as select table_name, column_name, column_type
from information_schema.columns where table_name = 'proc';
select * from t115;
table_name	column_name	column_type
proc	db	char(64)
proc	name	char(64)
proc	type	enum('FUNCTION','PROCEDURE')
proc	specific_name	char(64)
proc	language	enum('SQL')
proc	sql_data_access	enum('CONTAINS_SQL','NO_SQL','READS_SQL_DATA','MODIFIES_SQL_DATA')
proc	is_deterministic	enum('YES','NO')
proc	security_type	enum('INVOKER','DEFINER')
proc	param_list	blob
proc	returns	longblob
proc	body	longblob
proc	definer	char(77)
proc	created	timestamp
proc	modified	timestamp
proc	sql_mode	set('REAL_AS_FLOAT','PIPES_AS_CONCAT','ANSI_QUOTES','IGNORE_SPACE','NOT_USED','ONLY_FULL_GROUP_BY','NO_UNSIGNED_SUBTRACTION','NO_DIR_IN_CREATE','POSTGRESQL','ORACLE','MSSQL','DB2','MAXDB','NO_KEY_OPTIONS','NO_TABLE_OPTIONS','NO_FIELD_OPTIONS','MYSQL323','MYSQL40','ANSI','NO_AUTO_VALUE_ON_ZERO','NO_BACKSLASH_ESCAPES','STRICT_TRANS_TABLES','STRICT_ALL_TABLES','NO_ZERO_IN_DATE','NO_ZERO_DATE','INVALID_DATES','ERROR_FOR_DIVISION_BY_ZERO','TRADITIONAL','NO_AUTO_CREATE_USER','HIGH_NOT_PRECEDENCE')
proc	comment	char(64)
proc	character_set_client	char(32)
proc	collation_connection	char(32)
proc	db_collation	char(32)
proc	body_utf8	longblob
drop table t115;
create procedure p108 () begin declare c cursor for select data_type
from information_schema.columns;  open c; open c; end;//
call p108()//
ERROR 24000: Cursor is already open
drop procedure p108;
create view v1 as select A1.table_name from information_schema.TABLES A1
where table_name= "user";
select * from v1;
table_name
user
drop view v1;
create view vo as select 'a' union select 'a';
show index from vo;
Table	Non_unique	Key_name	Seq_in_index	Column_name	Collation	Cardinality	Sub_part	Packed	Null	Index_type	Comment
select * from information_schema.TABLE_CONSTRAINTS where
TABLE_NAME= "vo";
CONSTRAINT_CATALOG	CONSTRAINT_SCHEMA	CONSTRAINT_NAME	TABLE_SCHEMA	TABLE_NAME	CONSTRAINT_TYPE
select * from information_schema.KEY_COLUMN_USAGE where
TABLE_NAME= "vo";
CONSTRAINT_CATALOG	CONSTRAINT_SCHEMA	CONSTRAINT_NAME	TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	COLUMN_NAME	ORDINAL_POSITION	POSITION_IN_UNIQUE_CONSTRAINT	REFERENCED_TABLE_SCHEMA	REFERENCED_TABLE_NAME	REFERENCED_COLUMN_NAME
drop view vo;
select TABLE_NAME,TABLE_TYPE,ENGINE
from information_schema.tables 
where table_schema='information_schema' limit 2;
TABLE_NAME	TABLE_TYPE	ENGINE
CHARACTER_SETS	SYSTEM VIEW	MEMORY
COLLATIONS	SYSTEM VIEW	MEMORY
show tables from information_schema like "T%";
Tables_in_information_schema (T%)
TABLES
TABLE_CONSTRAINTS
TABLE_PRIVILEGES
TRIGGERS
create database information_schema;
ERROR 42000: Access denied for user 'root'@'localhost' to database 'information_schema'
use information_schema;
show full tables like "T%";
Tables_in_information_schema (T%)	Table_type
TABLES	SYSTEM VIEW
TABLE_CONSTRAINTS	SYSTEM VIEW
TABLE_PRIVILEGES	SYSTEM VIEW
TRIGGERS	SYSTEM VIEW
create table t1(a int);
ERROR 42S02: Unknown table 't1' in information_schema
use test;
show tables;
Tables_in_test
use information_schema;
show tables like "T%";
Tables_in_information_schema (T%)
TABLES
TABLE_CONSTRAINTS
TABLE_PRIVILEGES
TRIGGERS
select table_name from tables where table_name='user';
table_name
user
select column_name, privileges from columns
where table_name='user' and column_name like '%o%';
column_name	privileges
Host	select,insert,update,references
Password	select,insert,update,references
Drop_priv	select,insert,update,references
Reload_priv	select,insert,update,references
Shutdown_priv	select,insert,update,references
Process_priv	select,insert,update,references
Show_db_priv	select,insert,update,references
Lock_tables_priv	select,insert,update,references
Show_view_priv	select,insert,update,references
Create_routine_priv	select,insert,update,references
Alter_routine_priv	select,insert,update,references
max_questions	select,insert,update,references
max_connections	select,insert,update,references
max_user_connections	select,insert,update,references
use test;
create function sub1(i int) returns int
return i+1;
create table t1(f1 int);
create view v2 (c) as select f1 from t1;
create view v3 (c) as select sub1(1);
create table t4(f1 int, KEY f1_key (f1));
drop table t1;
drop function sub1;
select table_name from information_schema.views
where table_schema='test';
table_name
v2
v3
select table_name from information_schema.views
where table_schema='test';
table_name
v2
v3
select column_name from information_schema.columns
where table_schema='test';
column_name
f1
Warnings:
Warning	1356	View 'test.v2' references invalid table(s) or column(s) or function(s) or definer/invoker of view lack rights to use them
Warning	1356	View 'test.v3' references invalid table(s) or column(s) or function(s) or definer/invoker of view lack rights to use them
select index_name from information_schema.statistics where table_schema='test';
index_name
f1_key
select constraint_name from information_schema.table_constraints
where table_schema='test';
constraint_name
show create view v2;
View	Create View	character_set_client	collation_connection
v2	CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `v2` AS select `test`.`t1`.`f1` AS `c` from `t1`	latin1	latin1_swedish_ci
Warnings:
Warning	1356	View 'test.v2' references invalid table(s) or column(s) or function(s) or definer/invoker of view lack rights to use them
show create table v3;
View	Create View	character_set_client	collation_connection
v3	CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `v3` AS select `sub1`(1) AS `c`	latin1	latin1_swedish_ci
Warnings:
Warning	1356	View 'test.v3' references invalid table(s) or column(s) or function(s) or definer/invoker of view lack rights to use them
drop view v2;
drop view v3;
drop table t4;
select * from information_schema.table_names;
ERROR 42S02: Unknown table 'table_names' in information_schema
select column_type from information_schema.columns
where table_schema="information_schema" and table_name="COLUMNS" and
(column_name="character_set_name" or column_name="collation_name");
column_type
varchar(64)
varchar(64)
select TABLE_ROWS from information_schema.tables where 
table_schema="information_schema" and table_name="COLUMNS";
TABLE_ROWS
NULL
select table_type from information_schema.tables
where table_schema="mysql" and table_name="user";
table_type
BASE TABLE
show open tables where `table` like "user";
Database	Table	In_use	Name_locked
mysql	user	0	0
show status where variable_name like "%database%";
Variable_name	Value
Com_show_databases	3
show variables where variable_name like "skip_show_databas";
Variable_name	Value
show global status like "Threads_running";
Variable_name	Value
Threads_running	#
create table t1(f1 int);
create table t2(f2 int);
create view v1 as select * from t1, t2;
set @got_val= (select count(*) from information_schema.columns);
drop view v1;
drop table t1, t2;
use test;
CREATE TABLE t_crashme ( f1 BIGINT);
CREATE VIEW a1 (t_CRASHME) AS SELECT f1 FROM t_crashme GROUP BY f1;
CREATE VIEW a2 AS SELECT t_CRASHME FROM a1;
count(*)
68
drop view a2, a1;
drop table t_crashme;
select table_schema,table_name, column_name from
information_schema.columns 
where data_type = 'longtext';
table_schema	table_name	column_name
information_schema	COLUMNS	COLUMN_DEFAULT
information_schema	COLUMNS	COLUMN_TYPE
information_schema	EVENTS	EVENT_DEFINITION
information_schema	EVENTS	SQL_MODE
information_schema	PARTITIONS	PARTITION_EXPRESSION
information_schema	PARTITIONS	SUBPARTITION_EXPRESSION
information_schema	PARTITIONS	PARTITION_DESCRIPTION
information_schema	PLUGINS	PLUGIN_DESCRIPTION
information_schema	PROCESSLIST	INFO
information_schema	ROUTINES	ROUTINE_DEFINITION
information_schema	ROUTINES	SQL_MODE
information_schema	TRIGGERS	ACTION_CONDITION
information_schema	TRIGGERS	ACTION_STATEMENT
information_schema	TRIGGERS	SQL_MODE
information_schema	TRIGGERS	DEFINER
information_schema	VIEWS	VIEW_DEFINITION
select table_name, column_name, data_type from information_schema.columns
where data_type = 'datetime';
table_name	column_name	data_type
EVENTS	EXECUTE_AT	datetime
EVENTS	STARTS	datetime
EVENTS	ENDS	datetime
EVENTS	CREATED	datetime
EVENTS	LAST_ALTERED	datetime
EVENTS	LAST_EXECUTED	datetime
FILES	CREATION_TIME	datetime
FILES	LAST_UPDATE_TIME	datetime
FILES	LAST_ACCESS_TIME	datetime
FILES	CREATE_TIME	datetime
FILES	UPDATE_TIME	datetime
FILES	CHECK_TIME	datetime
PARTITIONS	CREATE_TIME	datetime
PARTITIONS	UPDATE_TIME	datetime
PARTITIONS	CHECK_TIME	datetime
ROUTINES	CREATED	datetime
ROUTINES	LAST_ALTERED	datetime
TABLES	CREATE_TIME	datetime
TABLES	UPDATE_TIME	datetime
TABLES	CHECK_TIME	datetime
TRIGGERS	CREATED	datetime
event	execute_at	datetime
event	last_executed	datetime
event	starts	datetime
event	ends	datetime
SELECT COUNT(*) FROM INFORMATION_SCHEMA.TABLES A
WHERE NOT EXISTS 
(SELECT * FROM INFORMATION_SCHEMA.COLUMNS B
WHERE A.TABLE_SCHEMA = B.TABLE_SCHEMA
AND A.TABLE_NAME = B.TABLE_NAME);
COUNT(*)
0
create table t1
( x_bigint BIGINT,
x_integer INTEGER,
x_smallint SMALLINT,
x_decimal DECIMAL(5,3),
x_numeric NUMERIC(5,3),
x_real REAL,
x_float FLOAT,
x_double_precision DOUBLE PRECISION );
SELECT COLUMN_NAME, CHARACTER_MAXIMUM_LENGTH, CHARACTER_OCTET_LENGTH
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_NAME= 't1';
COLUMN_NAME	CHARACTER_MAXIMUM_LENGTH	CHARACTER_OCTET_LENGTH
x_bigint	NULL	NULL
x_integer	NULL	NULL
x_smallint	NULL	NULL
x_decimal	NULL	NULL
x_numeric	NULL	NULL
x_real	NULL	NULL
x_float	NULL	NULL
x_double_precision	NULL	NULL
drop table t1;
grant select on test.* to mysqltest_4@localhost;
SELECT TABLE_NAME, COLUMN_NAME, PRIVILEGES FROM INFORMATION_SCHEMA.COLUMNS 
where COLUMN_NAME='TABLE_NAME';
TABLE_NAME	COLUMN_NAME	PRIVILEGES
COLUMNS	TABLE_NAME	select
COLUMN_PRIVILEGES	TABLE_NAME	select
FILES	TABLE_NAME	select
KEY_COLUMN_USAGE	TABLE_NAME	select
PARTITIONS	TABLE_NAME	select
REFERENTIAL_CONSTRAINTS	TABLE_NAME	select
STATISTICS	TABLE_NAME	select
TABLES	TABLE_NAME	select
TABLE_CONSTRAINTS	TABLE_NAME	select
TABLE_PRIVILEGES	TABLE_NAME	select
VIEWS	TABLE_NAME	select
delete from mysql.user where user='mysqltest_4';
delete from mysql.db where user='mysqltest_4';
flush privileges;
SELECT table_schema, count(*) FROM information_schema.TABLES where table_name<>'ndb_binlog_index' AND table_name<>'ndb_apply_status' GROUP BY TABLE_SCHEMA;
table_schema	count(*)
information_schema	27
mysql	22
create table t1 (i int, j int);
create trigger trg1 before insert on t1 for each row
begin
if new.j > 10 then
set new.j := 10;
end if;
end|
create trigger trg2 before update on t1 for each row
begin
if old.i % 2 = 0 then
set new.j := -1;
end if;
end|
create trigger trg3 after update on t1 for each row
begin
if new.j = -1 then
set @fired:= "Yes";
end if;
end|
show triggers;
Trigger	Event	Table	Statement	Timing	Created	sql_mode	Definer	character_set_client	collation_connection	Database Collation
trg1	INSERT	t1	begin
if new.j > 10 then
set new.j := 10;
end if;
end	BEFORE	NULL		root@localhost	latin1	latin1_swedish_ci	latin1_swedish_ci
trg2	UPDATE	t1	begin
if old.i % 2 = 0 then
set new.j := -1;
end if;
end	BEFORE	NULL		root@localhost	latin1	latin1_swedish_ci	latin1_swedish_ci
trg3	UPDATE	t1	begin
if new.j = -1 then
set @fired:= "Yes";
end if;
end	AFTER	NULL		root@localhost	latin1	latin1_swedish_ci	latin1_swedish_ci
select * from information_schema.triggers;
TRIGGER_CATALOG	TRIGGER_SCHEMA	TRIGGER_NAME	EVENT_MANIPULATION	EVENT_OBJECT_CATALOG	EVENT_OBJECT_SCHEMA	EVENT_OBJECT_TABLE	ACTION_ORDER	ACTION_CONDITION	ACTION_STATEMENT	ACTION_ORIENTATION	ACTION_TIMING	ACTION_REFERENCE_OLD_TABLE	ACTION_REFERENCE_NEW_TABLE	ACTION_REFERENCE_OLD_ROW	ACTION_REFERENCE_NEW_ROW	CREATED	SQL_MODE	DEFINER	CHARACTER_SET_CLIENT	COLLATION_CONNECTION	DATABASE_COLLATION
NULL	test	trg1	INSERT	NULL	test	t1	0	NULL	begin
if new.j > 10 then
set new.j := 10;
end if;
end	ROW	BEFORE	NULL	NULL	OLD	NEW	NULL		root@localhost	latin1	latin1_swedish_ci	latin1_swedish_ci
NULL	test	trg2	UPDATE	NULL	test	t1	0	NULL	begin
if old.i % 2 = 0 then
set new.j := -1;
end if;
end	ROW	BEFORE	NULL	NULL	OLD	NEW	NULL		root@localhost	latin1	latin1_swedish_ci	latin1_swedish_ci
NULL	test	trg3	UPDATE	NULL	test	t1	0	NULL	begin
if new.j = -1 then
set @fired:= "Yes";
end if;
end	ROW	AFTER	NULL	NULL	OLD	NEW	NULL		root@localhost	latin1	latin1_swedish_ci	latin1_swedish_ci
drop trigger trg1;
drop trigger trg2;
drop trigger trg3;
drop table t1;
create database mysqltest;
create table mysqltest.t1 (f1 int, f2 int);
create table mysqltest.t2 (f1 int);
grant select (f1) on mysqltest.t1 to user1@localhost;
grant select on mysqltest.t2 to user2@localhost;
grant select on mysqltest.* to user3@localhost;
grant select on *.* to user4@localhost;
select * from information_schema.column_privileges order by grantee;
GRANTEE	TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	COLUMN_NAME	PRIVILEGE_TYPE	IS_GRANTABLE
'user1'@'localhost'	NULL	mysqltest	t1	f1	SELECT	NO
select * from information_schema.table_privileges order by grantee;
GRANTEE	TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	PRIVILEGE_TYPE	IS_GRANTABLE
select * from information_schema.schema_privileges order by grantee;
GRANTEE	TABLE_CATALOG	TABLE_SCHEMA	PRIVILEGE_TYPE	IS_GRANTABLE
select * from information_schema.user_privileges order by grantee;
GRANTEE	TABLE_CATALOG	PRIVILEGE_TYPE	IS_GRANTABLE
'user1'@'localhost'	NULL	USAGE	NO
show grants;
Grants for user1@localhost
GRANT USAGE ON *.* TO 'user1'@'localhost'
GRANT SELECT (f1) ON `mysqltest`.`t1` TO 'user1'@'localhost'
select * from information_schema.column_privileges order by grantee;
GRANTEE	TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	COLUMN_NAME	PRIVILEGE_TYPE	IS_GRANTABLE
select * from information_schema.table_privileges order by grantee;
GRANTEE	TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	PRIVILEGE_TYPE	IS_GRANTABLE
'user2'@'localhost'	NULL	mysqltest	t2	SELECT	NO
select * from information_schema.schema_privileges order by grantee;
GRANTEE	TABLE_CATALOG	TABLE_SCHEMA	PRIVILEGE_TYPE	IS_GRANTABLE
select * from information_schema.user_privileges order by grantee;
GRANTEE	TABLE_CATALOG	PRIVILEGE_TYPE	IS_GRANTABLE
'user2'@'localhost'	NULL	USAGE	NO
show grants;
Grants for user2@localhost
GRANT USAGE ON *.* TO 'user2'@'localhost'
GRANT SELECT ON `mysqltest`.`t2` TO 'user2'@'localhost'
select * from information_schema.column_privileges order by grantee;
GRANTEE	TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	COLUMN_NAME	PRIVILEGE_TYPE	IS_GRANTABLE
select * from information_schema.table_privileges order by grantee;
GRANTEE	TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	PRIVILEGE_TYPE	IS_GRANTABLE
select * from information_schema.schema_privileges order by grantee;
GRANTEE	TABLE_CATALOG	TABLE_SCHEMA	PRIVILEGE_TYPE	IS_GRANTABLE
'user3'@'localhost'	NULL	mysqltest	SELECT	NO
select * from information_schema.user_privileges order by grantee;
GRANTEE	TABLE_CATALOG	PRIVILEGE_TYPE	IS_GRANTABLE
'user3'@'localhost'	NULL	USAGE	NO
show grants;
Grants for user3@localhost
GRANT USAGE ON *.* TO 'user3'@'localhost'
GRANT SELECT ON `mysqltest`.* TO 'user3'@'localhost'
select * from information_schema.column_privileges where grantee like '%user%'
order by grantee;
GRANTEE	TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	COLUMN_NAME	PRIVILEGE_TYPE	IS_GRANTABLE
'user1'@'localhost'	NULL	mysqltest	t1	f1	SELECT	NO
select * from information_schema.table_privileges where grantee like '%user%'
order by grantee;
GRANTEE	TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	PRIVILEGE_TYPE	IS_GRANTABLE
'user2'@'localhost'	NULL	mysqltest	t2	SELECT	NO
select * from information_schema.schema_privileges where grantee like '%user%'
order by grantee;
GRANTEE	TABLE_CATALOG	TABLE_SCHEMA	PRIVILEGE_TYPE	IS_GRANTABLE
'user3'@'localhost'	NULL	mysqltest	SELECT	NO
select * from information_schema.user_privileges where grantee like '%user%'
order by grantee;
GRANTEE	TABLE_CATALOG	PRIVILEGE_TYPE	IS_GRANTABLE
'user1'@'localhost'	NULL	USAGE	NO
'user2'@'localhost'	NULL	USAGE	NO
'user3'@'localhost'	NULL	USAGE	NO
'user4'@'localhost'	NULL	SELECT	NO
show grants;
Grants for user4@localhost
GRANT SELECT ON *.* TO 'user4'@'localhost'
drop user user1@localhost, user2@localhost, user3@localhost, user4@localhost;
use test;
drop database mysqltest;
drop procedure if exists p1;
drop procedure if exists p2;
create procedure p1 () modifies sql data set @a = 5;
create procedure p2 () set @a = 5;
select sql_data_access from information_schema.routines
where specific_name like 'p%';
sql_data_access
MODIFIES SQL DATA
CONTAINS SQL
drop procedure p1;
drop procedure p2;
show create database information_schema;
Database	Create Database
information_schema	CREATE DATABASE `information_schema` /*!40100 DEFAULT CHARACTER SET utf8 */
create table t1(f1 LONGBLOB, f2 LONGTEXT);
select column_name,data_type,CHARACTER_OCTET_LENGTH,
CHARACTER_MAXIMUM_LENGTH
from information_schema.columns
where table_name='t1';
column_name	data_type	CHARACTER_OCTET_LENGTH	CHARACTER_MAXIMUM_LENGTH
f1	longblob	4294967295	4294967295
f2	longtext	4294967295	4294967295
drop table t1;
create table t1(f1 tinyint, f2 SMALLINT, f3 mediumint, f4 int,
f5 BIGINT, f6 BIT, f7 bit(64));
select column_name, NUMERIC_PRECISION, NUMERIC_SCALE
from information_schema.columns
where table_name='t1';
column_name	NUMERIC_PRECISION	NUMERIC_SCALE
f1	3	0
f2	5	0
f3	7	0
f4	10	0
f5	19	0
f6	1	NULL
f7	64	NULL
drop table t1;
create table t1 (f1 integer);
create trigger tr1 after insert on t1 for each row set @test_var=42;
use information_schema;
select trigger_schema, trigger_name from triggers where
trigger_name='tr1';
trigger_schema	trigger_name
test	tr1
use test;
drop table t1;
create table t1 (a int not null, b int);
use information_schema;
select column_name, column_default from columns
where table_schema='test' and table_name='t1';
column_name	column_default
a	NULL
b	NULL
use test;
show columns from t1;
Field	Type	Null	Key	Default	Extra
a	int(11)	NO		NULL	
b	int(11)	YES		NULL	
drop table t1;
CREATE TABLE t1 (a int);
CREATE TABLE t2 (b int);
SHOW TABLE STATUS FROM test
WHERE name IN ( SELECT TABLE_NAME FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_SCHEMA='test' AND TABLE_TYPE='BASE TABLE');
Name	Engine	Version	Row_format	Rows	Avg_row_length	Data_length	Max_data_length	Index_length	Data_free	Auto_increment	Create_time	Update_time	Check_time	Collation	Checksum	Create_options	Comment
t1	MyISAM	10	Fixed	0	0	0	#	1024	0	NULL	#	#	NULL	latin1_swedish_ci	NULL		
t2	MyISAM	10	Fixed	0	0	0	#	1024	0	NULL	#	#	NULL	latin1_swedish_ci	NULL		
DROP TABLE t1,t2;
create table t1(f1 int);
create view v1 (c) as select f1 from t1;
select database();
database()
NULL
show fields from test.v1;
Field	Type	Null	Key	Default	Extra
c	int(11)	YES		NULL	
drop view v1;
drop table t1;
alter database information_schema;
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 1
drop database information_schema;
ERROR 42000: Access denied for user 'root'@'localhost' to database 'information_schema'
drop table information_schema.tables;
ERROR 42000: Access denied for user 'root'@'localhost' to database 'information_schema'
alter table information_schema.tables;
ERROR 42000: Access denied for user 'root'@'localhost' to database 'information_schema'
use information_schema;
create temporary table schemata(f1 char(10));
ERROR 42000: Access denied for user 'root'@'localhost' to database 'information_schema'
CREATE PROCEDURE p1 ()
BEGIN
SELECT 'foo' FROM DUAL;
END |
ERROR 42000: Unknown database 'information_schema'
select  ROUTINE_NAME from routines;
ROUTINE_NAME
grant all on information_schema.* to 'user1'@'localhost';
ERROR 42000: Access denied for user 'root'@'localhost' to database 'information_schema'
grant select on information_schema.* to 'user1'@'localhost';
ERROR 42000: Access denied for user 'root'@'localhost' to database 'information_schema'
use test;
create table t1(id int);
insert into t1(id) values (1);
select 1 from (select 1 from test.t1) a;
1
1
use information_schema;
select 1 from (select 1 from test.t1) a;
1
1
use test;
drop table t1;
create table t1 (f1 int(11));
create view v1 as select * from t1;
drop table t1;
select table_type from information_schema.tables
where table_name="v1";
table_type
VIEW
drop view v1;
create temporary table t1(f1 int, index(f1));
show columns from t1;
Field	Type	Null	Key	Default	Extra
f1	int(11)	YES	MUL	NULL	
describe t1;
Field	Type	Null	Key	Default	Extra
f1	int(11)	YES	MUL	NULL	
show indexes from t1;
Table	Non_unique	Key_name	Seq_in_index	Column_name	Collation	Cardinality	Sub_part	Packed	Null	Index_type	Comment
t1	1	f1	1	f1	A	NULL	NULL	NULL	YES	BTREE	
drop table t1;
create table t1(f1 binary(32), f2 varbinary(64));
select character_maximum_length, character_octet_length
from information_schema.columns where table_name='t1';
character_maximum_length	character_octet_length
32	32
64	64
drop table t1;
CREATE TABLE t1 (f1 BIGINT, f2 VARCHAR(20), f3 BIGINT);
INSERT INTO t1 SET f1 = 1, f2 = 'Schoenenbourg', f3 = 1;
CREATE FUNCTION func2() RETURNS BIGINT RETURN 1;
CREATE FUNCTION func1() RETURNS BIGINT
BEGIN
RETURN ( SELECT COUNT(*) FROM INFORMATION_SCHEMA.VIEWS);
END//
CREATE VIEW v1 AS SELECT 1 FROM t1
WHERE f3 = (SELECT func2 ());
SELECT func1();
func1()
1
DROP TABLE t1;
DROP VIEW v1;
DROP FUNCTION func1;
DROP FUNCTION func2;
select column_type, group_concat(table_schema, '.', table_name), count(*) as num
from information_schema.columns where
table_schema='information_schema' and
(column_type = 'varchar(7)' or column_type = 'varchar(20)')
group by column_type order by num;
column_type	group_concat(table_schema, '.', table_name)	num
varchar(7)	information_schema.ROUTINES,information_schema.VIEWS	2
varchar(20)	information_schema.COLUMNS,information_schema.FILES,information_schema.FILES,information_schema.PLUGINS,information_schema.PLUGINS,information_schema.PLUGINS	6
create table t1(f1 char(1) not null, f2 char(9) not null)
default character set utf8;
select CHARACTER_MAXIMUM_LENGTH, CHARACTER_OCTET_LENGTH from
information_schema.columns where table_schema='test' and table_name = 't1';
CHARACTER_MAXIMUM_LENGTH	CHARACTER_OCTET_LENGTH
1	3
9	27
drop table t1;
use mysql;
INSERT INTO `proc` VALUES ('test','','PROCEDURE','','SQL','CONTAINS_SQL',
'NO','DEFINER','','','BEGIN\r\n  \r\nEND','root@%','2006-03-02 18:40:03',
'2006-03-02 18:40:03','','','utf8','utf8_general_ci','utf8_general_ci','n/a');
select routine_name from information_schema.routines;
routine_name

delete from proc where name='';
use test;
grant select on test.* to mysqltest_1@localhost;
create table t1 (id int);
create view v1 as select * from t1;
create definer = mysqltest_1@localhost
sql security definer view v2 as select 1;
select * from information_schema.views
where table_name='v1' or table_name='v2';
TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	VIEW_DEFINITION	CHECK_OPTION	IS_UPDATABLE	DEFINER	SECURITY_TYPE	CHARACTER_SET_CLIENT	COLLATION_CONNECTION
NULL	test	v1		NONE	YES	root@localhost	DEFINER	latin1	latin1_swedish_ci
NULL	test	v2	select 1	NONE	NO	mysqltest_1@localhost	DEFINER	latin1	latin1_swedish_ci
drop view v1, v2;
drop table t1;
drop user mysqltest_1@localhost;
set @a:= '.';
create table t1(f1 char(5));
create table t2(f1 char(5));
select concat(@a, table_name), @a, table_name
from information_schema.tables where table_schema = 'test';
concat(@a, table_name)	@a	table_name
.t1	.	t1
.t2	.	t2
drop table t1,t2;
DROP PROCEDURE IF EXISTS p1;
DROP FUNCTION IF EXISTS f1;
CREATE PROCEDURE p1() SET @a= 1;
CREATE FUNCTION f1() RETURNS INT RETURN @a + 1;
CREATE USER mysql_bug20230@localhost;
GRANT EXECUTE ON PROCEDURE p1 TO mysql_bug20230@localhost;
GRANT EXECUTE ON FUNCTION f1 TO mysql_bug20230@localhost;
SELECT ROUTINE_NAME, ROUTINE_DEFINITION FROM INFORMATION_SCHEMA.ROUTINES;
ROUTINE_NAME	ROUTINE_DEFINITION
f1	RETURN @a + 1
p1	SET @a= 1
SHOW CREATE PROCEDURE p1;
Procedure	sql_mode	Create Procedure	character_set_client	collation_connection	Database Collation
p1		CREATE DEFINER=`root`@`localhost` PROCEDURE `p1`()
SET @a= 1	latin1	latin1_swedish_ci	latin1_swedish_ci
SHOW CREATE FUNCTION f1;
Function	sql_mode	Create Function	character_set_client	collation_connection	Database Collation
f1		CREATE DEFINER=`root`@`localhost` FUNCTION `f1`() RETURNS int(11)
RETURN @a + 1	latin1	latin1_swedish_ci	latin1_swedish_ci
SELECT ROUTINE_NAME, ROUTINE_DEFINITION FROM INFORMATION_SCHEMA.ROUTINES;
ROUTINE_NAME	ROUTINE_DEFINITION
f1	NULL
p1	NULL
SHOW CREATE PROCEDURE p1;
Procedure	sql_mode	Create Procedure	character_set_client	collation_connection	Database Collation
p1		NULL	latin1	latin1_swedish_ci	latin1_swedish_ci
SHOW CREATE FUNCTION f1;
Function	sql_mode	Create Function	character_set_client	collation_connection	Database Collation
f1		NULL	latin1	latin1_swedish_ci	latin1_swedish_ci
CALL p1();
SELECT f1();
f1()
2
DROP FUNCTION f1;
DROP PROCEDURE p1;
DROP USER mysql_bug20230@localhost;
SELECT t.table_name, c1.column_name
FROM information_schema.tables t
INNER JOIN
information_schema.columns c1
ON t.table_schema = c1.table_schema AND
t.table_name = c1.table_name
WHERE t.table_schema = 'information_schema' AND
c1.ordinal_position =
( SELECT COALESCE(MIN(c2.ordinal_position),1)
FROM information_schema.columns c2
WHERE c2.table_schema = t.table_schema AND
c2.table_name = t.table_name AND
c2.column_name LIKE '%SCHEMA%'
        );
table_name	column_name
CHARACTER_SETS	CHARACTER_SET_NAME
COLLATIONS	COLLATION_NAME
COLLATION_CHARACTER_SET_APPLICABILITY	COLLATION_NAME
COLUMNS	TABLE_SCHEMA
COLUMN_PRIVILEGES	TABLE_SCHEMA
ENGINES	ENGINE
EVENTS	EVENT_SCHEMA
FILES	TABLE_SCHEMA
GLOBAL_STATUS	VARIABLE_NAME
GLOBAL_VARIABLES	VARIABLE_NAME
KEY_COLUMN_USAGE	CONSTRAINT_SCHEMA
PARTITIONS	TABLE_SCHEMA
PLUGINS	PLUGIN_NAME
PROCESSLIST	ID
REFERENTIAL_CONSTRAINTS	CONSTRAINT_SCHEMA
ROUTINES	ROUTINE_SCHEMA
SCHEMATA	SCHEMA_NAME
SCHEMA_PRIVILEGES	TABLE_SCHEMA
SESSION_STATUS	VARIABLE_NAME
SESSION_VARIABLES	VARIABLE_NAME
STATISTICS	TABLE_SCHEMA
TABLES	TABLE_SCHEMA
TABLE_CONSTRAINTS	CONSTRAINT_SCHEMA
TABLE_PRIVILEGES	TABLE_SCHEMA
TRIGGERS	TRIGGER_SCHEMA
USER_PRIVILEGES	GRANTEE
VIEWS	TABLE_SCHEMA
SELECT t.table_name, c1.column_name
FROM information_schema.tables t
INNER JOIN
information_schema.columns c1
ON t.table_schema = c1.table_schema AND
t.table_name = c1.table_name
WHERE t.table_schema = 'information_schema' AND
c1.ordinal_position =
( SELECT COALESCE(MIN(c2.ordinal_position),1)
FROM information_schema.columns c2
WHERE c2.table_schema = 'information_schema' AND
c2.table_name = t.table_name AND
c2.column_name LIKE '%SCHEMA%'
        );
table_name	column_name
CHARACTER_SETS	CHARACTER_SET_NAME
COLLATIONS	COLLATION_NAME
COLLATION_CHARACTER_SET_APPLICABILITY	COLLATION_NAME
COLUMNS	TABLE_SCHEMA
COLUMN_PRIVILEGES	TABLE_SCHEMA
ENGINES	ENGINE
EVENTS	EVENT_SCHEMA
FILES	TABLE_SCHEMA
GLOBAL_STATUS	VARIABLE_NAME
GLOBAL_VARIABLES	VARIABLE_NAME
KEY_COLUMN_USAGE	CONSTRAINT_SCHEMA
PARTITIONS	TABLE_SCHEMA
PLUGINS	PLUGIN_NAME
PROCESSLIST	ID
REFERENTIAL_CONSTRAINTS	CONSTRAINT_SCHEMA
ROUTINES	ROUTINE_SCHEMA
SCHEMATA	SCHEMA_NAME
SCHEMA_PRIVILEGES	TABLE_SCHEMA
SESSION_STATUS	VARIABLE_NAME
SESSION_VARIABLES	VARIABLE_NAME
STATISTICS	TABLE_SCHEMA
TABLES	TABLE_SCHEMA
TABLE_CONSTRAINTS	CONSTRAINT_SCHEMA
TABLE_PRIVILEGES	TABLE_SCHEMA
TRIGGERS	TRIGGER_SCHEMA
USER_PRIVILEGES	GRANTEE
VIEWS	TABLE_SCHEMA
SELECT MAX(table_name) FROM information_schema.tables;
MAX(table_name)
VIEWS
SELECT table_name from information_schema.tables
WHERE table_name=(SELECT MAX(table_name)
FROM information_schema.tables);
table_name
VIEWS
DROP TABLE IF EXISTS bug23037;
DROP FUNCTION IF EXISTS get_value;
SELECT COLUMN_NAME, MD5(COLUMN_DEFAULT), LENGTH(COLUMN_DEFAULT) FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME='bug23037';
COLUMN_NAME	MD5(COLUMN_DEFAULT)	LENGTH(COLUMN_DEFAULT)
fld1	7cf7a6782be951a1f2464a350da926a5	65532
SELECT MD5(get_value());
MD5(get_value())
7cf7a6782be951a1f2464a350da926a5
SELECT COLUMN_NAME, MD5(COLUMN_DEFAULT), LENGTH(COLUMN_DEFAULT), COLUMN_DEFAULT=get_value() FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME='bug23037';
COLUMN_NAME	MD5(COLUMN_DEFAULT)	LENGTH(COLUMN_DEFAULT)	COLUMN_DEFAULT=get_value()
fld1	7cf7a6782be951a1f2464a350da926a5	65532	1
DROP TABLE bug23037;
DROP FUNCTION get_value;
create view v1 as
select table_schema as object_schema,
table_name   as object_name,
table_type   as object_type
from information_schema.tables
order by object_schema;
explain select * from v1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	tables	ALL	NULL	NULL	NULL	NULL	NULL	Open_frm_only; Scanned all databases; Using filesort
explain select * from (select table_name from information_schema.tables) as a;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	<derived2>	system	NULL	NULL	NULL	NULL	0	const row not found
2	DERIVED	tables	ALL	NULL	NULL	NULL	NULL	NULL	Skip_open_table; Scanned all databases
drop view v1;
create table t1 (f1 int(11));
create table t2 (f1 int(11), f2 int(11));
select table_name from information_schema.tables
where table_schema = 'test' and table_name not in
(select table_name from information_schema.columns
where table_schema = 'test' and column_name = 'f3');
table_name
t1
t2
drop table t1,t2;
select 1 as f1 from information_schema.tables  where "CHARACTER_SETS"=
(select cast(table_name as char)  from information_schema.tables
order by table_name limit 1) limit 1;
f1
1
select t.table_name, group_concat(t.table_schema, '.', t.table_name),
count(*) as num1
from information_schema.tables t
inner join information_schema.columns c1
on t.table_schema = c1.table_schema AND t.table_name = c1.table_name
where t.table_schema = 'information_schema' and
c1.ordinal_position =
(select isnull(c2.column_type) -
isnull(group_concat(c2.table_schema, '.', c2.table_name)) +
count(*) as num
from information_schema.columns c2 where
c2.table_schema='information_schema' and
(c2.column_type = 'varchar(7)' or c2.column_type = 'varchar(20)')
group by c2.column_type order by num limit 1)
group by t.table_name order by num1, t.table_name;
table_name	group_concat(t.table_schema, '.', t.table_name)	num1
CHARACTER_SETS	information_schema.CHARACTER_SETS	1
COLLATIONS	information_schema.COLLATIONS	1
COLLATION_CHARACTER_SET_APPLICABILITY	information_schema.COLLATION_CHARACTER_SET_APPLICABILITY	1
COLUMNS	information_schema.COLUMNS	1
COLUMN_PRIVILEGES	information_schema.COLUMN_PRIVILEGES	1
ENGINES	information_schema.ENGINES	1
EVENTS	information_schema.EVENTS	1
FILES	information_schema.FILES	1
GLOBAL_STATUS	information_schema.GLOBAL_STATUS	1
GLOBAL_VARIABLES	information_schema.GLOBAL_VARIABLES	1
KEY_COLUMN_USAGE	information_schema.KEY_COLUMN_USAGE	1
PARTITIONS	information_schema.PARTITIONS	1
PLUGINS	information_schema.PLUGINS	1
PROCESSLIST	information_schema.PROCESSLIST	1
REFERENTIAL_CONSTRAINTS	information_schema.REFERENTIAL_CONSTRAINTS	1
ROUTINES	information_schema.ROUTINES	1
SCHEMATA	information_schema.SCHEMATA	1
SCHEMA_PRIVILEGES	information_schema.SCHEMA_PRIVILEGES	1
SESSION_STATUS	information_schema.SESSION_STATUS	1
SESSION_VARIABLES	information_schema.SESSION_VARIABLES	1
STATISTICS	information_schema.STATISTICS	1
TABLES	information_schema.TABLES	1
TABLE_CONSTRAINTS	information_schema.TABLE_CONSTRAINTS	1
TABLE_PRIVILEGES	information_schema.TABLE_PRIVILEGES	1
TRIGGERS	information_schema.TRIGGERS	1
USER_PRIVILEGES	information_schema.USER_PRIVILEGES	1
VIEWS	information_schema.VIEWS	1
create table t1(f1 int);
create view v1 as select f1+1 as a from t1;
create table t2 (f1 int, f2 int);
create view v2 as select f1+1 as a, f2 as b from t2;
select table_name, is_updatable from information_schema.views;
table_name	is_updatable
v1	NO
v2	YES
delete from v1;
drop view v1,v2;
drop table t1,t2;
alter database;
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 1
alter database test;
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 1
create database mysqltest;
create table mysqltest.t1(a int, b int, c int);
create trigger mysqltest.t1_ai after insert on mysqltest.t1
for each row set @a = new.a + new.b + new.c;
grant select(b) on mysqltest.t1 to mysqltest_1@localhost;
select trigger_name from information_schema.triggers
where event_object_table='t1';
trigger_name
t1_ai
show triggers from mysqltest;
Trigger	Event	Table	Statement	Timing	Created	sql_mode	Definer	character_set_client	collation_connection	Database Collation
t1_ai	INSERT	t1	set @a = new.a + new.b + new.c	AFTER	NULL		root@localhost	latin1	latin1_swedish_ci	latin1_swedish_ci
show columns from t1;
Field	Type	Null	Key	Default	Extra
b	int(11)	YES		NULL	
select column_name from information_schema.columns where table_name='t1';
column_name
b
show triggers;
Trigger	Event	Table	Statement	Timing	Created	sql_mode	Definer	character_set_client	collation_connection	Database Collation
select trigger_name from information_schema.triggers
where event_object_table='t1';
trigger_name
drop user mysqltest_1@localhost;
drop database mysqltest;
create table t1 (
f1 varchar(50),
f2 varchar(50) not null,
f3 varchar(50) default '',
f4 varchar(50) default NULL,
f5 bigint not null,
f6 bigint not null default 10,
f7 datetime not null,
f8 datetime default '2006-01-01'
);
select column_default from information_schema.columns where table_name= 't1';
column_default
NULL
NULL

NULL
NULL
10
NULL
2006-01-01 00:00:00
show columns from t1;
Field	Type	Null	Key	Default	Extra
f1	varchar(50)	YES		NULL	
f2	varchar(50)	NO		NULL	
f3	varchar(50)	YES			
f4	varchar(50)	YES		NULL	
f5	bigint(20)	NO		NULL	
f6	bigint(20)	NO		10	
f7	datetime	NO		NULL	
f8	datetime	YES		2006-01-01 00:00:00	
drop table t1;
End of 5.0 tests.
show fields from information_schema.table_names;
ERROR 42S02: Unknown table 'table_names' in information_schema
show keys from information_schema.table_names;
ERROR 42S02: Unknown table 'table_names' in information_schema
select * from information_schema.engines WHERE ENGINE="MyISAM";
ENGINE	SUPPORT	COMMENT	TRANSACTIONS	XA	SAVEPOINTS
MyISAM	DEFAULT	Default engine as of MySQL 3.23 with great performance	NO	NO	NO
grant select on *.* to user3148@localhost;
select user,db from information_schema.processlist;
user	db
user3148	test
drop user user3148@localhost;
DROP TABLE IF EXISTS server_status;
DROP EVENT IF EXISTS event_status;
SET GLOBAL event_scheduler=1;
CREATE EVENT event_status
ON SCHEDULE AT NOW()
ON COMPLETION NOT PRESERVE
DO
BEGIN
CREATE TABLE server_status
SELECT variable_name
FROM information_schema.global_status
WHERE variable_name LIKE 'ABORTED_CONNECTS' OR
variable_name LIKE 'BINLOG_CACHE_DISK_USE';
END$$
SELECT variable_name FROM server_status;
variable_name
ABORTED_CONNECTS
BINLOG_CACHE_DISK_USE
DROP TABLE server_status;
SET GLOBAL event_scheduler=0;
explain select table_name from information_schema.views where
table_schema='test' and table_name='v1';
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	views	ALL	NULL	TABLE_SCHEMA,TABLE_NAME	NULL	NULL	NULL	Using where; Open_frm_only; Scanned 0 databases
explain select * from information_schema.tables;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	tables	ALL	NULL	NULL	NULL	NULL	NULL	Open_full_table; Scanned all databases
explain select * from information_schema.collations;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	collations	ALL	NULL	NULL	NULL	NULL	NULL	
explain select * from information_schema.tables where
table_schema='test' and table_name= 't1';
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	tables	ALL	NULL	TABLE_SCHEMA,TABLE_NAME	NULL	NULL	NULL	Using where; Open_full_table; Scanned 0 databases
explain select table_name, table_type from information_schema.tables
where table_schema='test';
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	tables	ALL	NULL	TABLE_SCHEMA	NULL	NULL	NULL	Using where; Open_frm_only; Scanned 1 database
explain select b.table_name
from information_schema.tables a, information_schema.columns b
where a.table_name='t1' and a.table_schema='test' and b.table_name=a.table_name;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	a	ALL	NULL	TABLE_SCHEMA,TABLE_NAME	NULL	NULL	NULL	Using where; Skip_open_table; Scanned 0 databases
1	SIMPLE	b	ALL	NULL	NULL	NULL	NULL	NULL	Using where; Open_frm_only; Scanned all databases; Using join buffer
SELECT * FROM INFORMATION_SCHEMA.SCHEMATA
WHERE SCHEMA_NAME = 'mysqltest';
CATALOG_NAME	SCHEMA_NAME	DEFAULT_CHARACTER_SET_NAME	DEFAULT_COLLATION_NAME	SQL_PATH
SELECT * FROM INFORMATION_SCHEMA.SCHEMATA
WHERE SCHEMA_NAME = '';
CATALOG_NAME	SCHEMA_NAME	DEFAULT_CHARACTER_SET_NAME	DEFAULT_COLLATION_NAME	SQL_PATH
SELECT * FROM INFORMATION_SCHEMA.SCHEMATA
WHERE SCHEMA_NAME = 'test';
CATALOG_NAME	SCHEMA_NAME	DEFAULT_CHARACTER_SET_NAME	DEFAULT_COLLATION_NAME	SQL_PATH
NULL	test	latin1	latin1_swedish_ci	NULL
select count(*) from INFORMATION_SCHEMA.TABLES where TABLE_SCHEMA='mysql' AND TABLE_NAME='nonexisting';
count(*)
0
select count(*) from INFORMATION_SCHEMA.TABLES where TABLE_SCHEMA='mysql' AND TABLE_NAME='';
count(*)
0
select count(*) from INFORMATION_SCHEMA.TABLES where TABLE_SCHEMA='' AND TABLE_NAME='';
count(*)
0
select count(*) from INFORMATION_SCHEMA.TABLES where TABLE_SCHEMA='' AND TABLE_NAME='nonexisting';
count(*)
0
CREATE VIEW v1
AS SELECT *
FROM INFORMATION_SCHEMA.TABLES;
SELECT VIEW_DEFINITION FROM INFORMATION_SCHEMA.VIEWS where TABLE_NAME = 'v1';
VIEW_DEFINITION
SELECT *
FROM INFORMATION_SCHEMA.TABLES
DROP VIEW v1;
SELECT SCHEMA_NAME FROM INFORMATION_SCHEMA.SCHEMATA
WHERE SCHEMA_NAME ='information_schema';
SCHEMA_NAME
information_schema
SELECT TABLE_COLLATION FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_SCHEMA='mysql' and TABLE_NAME= 'db';
TABLE_COLLATION
utf8_bin
select * from information_schema.columns where table_schema = NULL;
TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	COLUMN_NAME	ORDINAL_POSITION	COLUMN_DEFAULT	IS_NULLABLE	DATA_TYPE	CHARACTER_MAXIMUM_LENGTH	CHARACTER_OCTET_LENGTH	NUMERIC_PRECISION	NUMERIC_SCALE	CHARACTER_SET_NAME	COLLATION_NAME	COLUMN_TYPE	COLUMN_KEY	EXTRA	PRIVILEGES	COLUMN_COMMENT
select * from `information_schema`.`COLUMNS` where `TABLE_NAME` = NULL;
TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	COLUMN_NAME	ORDINAL_POSITION	COLUMN_DEFAULT	IS_NULLABLE	DATA_TYPE	CHARACTER_MAXIMUM_LENGTH	CHARACTER_OCTET_LENGTH	NUMERIC_PRECISION	NUMERIC_SCALE	CHARACTER_SET_NAME	COLLATION_NAME	COLUMN_TYPE	COLUMN_KEY	EXTRA	PRIVILEGES	COLUMN_COMMENT
select * from `information_schema`.`KEY_COLUMN_USAGE` where `TABLE_SCHEMA` = NULL;
CONSTRAINT_CATALOG	CONSTRAINT_SCHEMA	CONSTRAINT_NAME	TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	COLUMN_NAME	ORDINAL_POSITION	POSITION_IN_UNIQUE_CONSTRAINT	REFERENCED_TABLE_SCHEMA	REFERENCED_TABLE_NAME	REFERENCED_COLUMN_NAME
select * from `information_schema`.`KEY_COLUMN_USAGE` where `TABLE_NAME` = NULL;
CONSTRAINT_CATALOG	CONSTRAINT_SCHEMA	CONSTRAINT_NAME	TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	COLUMN_NAME	ORDINAL_POSITION	POSITION_IN_UNIQUE_CONSTRAINT	REFERENCED_TABLE_SCHEMA	REFERENCED_TABLE_NAME	REFERENCED_COLUMN_NAME
select * from `information_schema`.`PARTITIONS` where `TABLE_SCHEMA` = NULL;
TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	PARTITION_NAME	SUBPARTITION_NAME	PARTITION_ORDINAL_POSITION	SUBPARTITION_ORDINAL_POSITION	PARTITION_METHOD	SUBPARTITION_METHOD	PARTITION_EXPRESSION	SUBPARTITION_EXPRESSION	PARTITION_DESCRIPTION	TABLE_ROWS	AVG_ROW_LENGTH	DATA_LENGTH	MAX_DATA_LENGTH	INDEX_LENGTH	DATA_FREE	CREATE_TIME	UPDATE_TIME	CHECK_TIME	CHECKSUM	PARTITION_COMMENT	NODEGROUP	TABLESPACE_NAME
select * from `information_schema`.`PARTITIONS` where `TABLE_NAME` = NULL;
TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	PARTITION_NAME	SUBPARTITION_NAME	PARTITION_ORDINAL_POSITION	SUBPARTITION_ORDINAL_POSITION	PARTITION_METHOD	SUBPARTITION_METHOD	PARTITION_EXPRESSION	SUBPARTITION_EXPRESSION	PARTITION_DESCRIPTION	TABLE_ROWS	AVG_ROW_LENGTH	DATA_LENGTH	MAX_DATA_LENGTH	INDEX_LENGTH	DATA_FREE	CREATE_TIME	UPDATE_TIME	CHECK_TIME	CHECKSUM	PARTITION_COMMENT	NODEGROUP	TABLESPACE_NAME
select * from `information_schema`.`REFERENTIAL_CONSTRAINTS` where `CONSTRAINT_SCHEMA` = NULL;
CONSTRAINT_CATALOG	CONSTRAINT_SCHEMA	CONSTRAINT_NAME	UNIQUE_CONSTRAINT_CATALOG	UNIQUE_CONSTRAINT_SCHEMA	UNIQUE_CONSTRAINT_NAME	MATCH_OPTION	UPDATE_RULE	DELETE_RULE	TABLE_NAME	REFERENCED_TABLE_NAME
select * from `information_schema`.`REFERENTIAL_CONSTRAINTS` where `TABLE_NAME` = NULL;
CONSTRAINT_CATALOG	CONSTRAINT_SCHEMA	CONSTRAINT_NAME	UNIQUE_CONSTRAINT_CATALOG	UNIQUE_CONSTRAINT_SCHEMA	UNIQUE_CONSTRAINT_NAME	MATCH_OPTION	UPDATE_RULE	DELETE_RULE	TABLE_NAME	REFERENCED_TABLE_NAME
select * from information_schema.schemata where schema_name = NULL;
CATALOG_NAME	SCHEMA_NAME	DEFAULT_CHARACTER_SET_NAME	DEFAULT_COLLATION_NAME	SQL_PATH
select * from `information_schema`.`STATISTICS` where `TABLE_SCHEMA` = NULL;
TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	NON_UNIQUE	INDEX_SCHEMA	INDEX_NAME	SEQ_IN_INDEX	COLUMN_NAME	COLLATION	CARDINALITY	SUB_PART	PACKED	NULLABLE	INDEX_TYPE	COMMENT
select * from `information_schema`.`STATISTICS` where `TABLE_NAME` = NULL;
TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	NON_UNIQUE	INDEX_SCHEMA	INDEX_NAME	SEQ_IN_INDEX	COLUMN_NAME	COLLATION	CARDINALITY	SUB_PART	PACKED	NULLABLE	INDEX_TYPE	COMMENT
select * from information_schema.tables where table_schema = NULL;
TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	TABLE_TYPE	ENGINE	VERSION	ROW_FORMAT	TABLE_ROWS	AVG_ROW_LENGTH	DATA_LENGTH	MAX_DATA_LENGTH	INDEX_LENGTH	DATA_FREE	AUTO_INCREMENT	CREATE_TIME	UPDATE_TIME	CHECK_TIME	TABLE_COLLATION	CHECKSUM	CREATE_OPTIONS	TABLE_COMMENT
select * from information_schema.tables where table_catalog = NULL;
TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	TABLE_TYPE	ENGINE	VERSION	ROW_FORMAT	TABLE_ROWS	AVG_ROW_LENGTH	DATA_LENGTH	MAX_DATA_LENGTH	INDEX_LENGTH	DATA_FREE	AUTO_INCREMENT	CREATE_TIME	UPDATE_TIME	CHECK_TIME	TABLE_COLLATION	CHECKSUM	CREATE_OPTIONS	TABLE_COMMENT
select * from information_schema.tables where table_name = NULL;
TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	TABLE_TYPE	ENGINE	VERSION	ROW_FORMAT	TABLE_ROWS	AVG_ROW_LENGTH	DATA_LENGTH	MAX_DATA_LENGTH	INDEX_LENGTH	DATA_FREE	AUTO_INCREMENT	CREATE_TIME	UPDATE_TIME	CHECK_TIME	TABLE_COLLATION	CHECKSUM	CREATE_OPTIONS	TABLE_COMMENT
select * from `information_schema`.`TABLE_CONSTRAINTS` where `TABLE_SCHEMA` = NULL;
CONSTRAINT_CATALOG	CONSTRAINT_SCHEMA	CONSTRAINT_NAME	TABLE_SCHEMA	TABLE_NAME	CONSTRAINT_TYPE
select * from `information_schema`.`TABLE_CONSTRAINTS` where `TABLE_NAME` = NULL;
CONSTRAINT_CATALOG	CONSTRAINT_SCHEMA	CONSTRAINT_NAME	TABLE_SCHEMA	TABLE_NAME	CONSTRAINT_TYPE
select * from `information_schema`.`TRIGGERS` where `EVENT_OBJECT_SCHEMA` = NULL;
TRIGGER_CATALOG	TRIGGER_SCHEMA	TRIGGER_NAME	EVENT_MANIPULATION	EVENT_OBJECT_CATALOG	EVENT_OBJECT_SCHEMA	EVENT_OBJECT_TABLE	ACTION_ORDER	ACTION_CONDITION	ACTION_STATEMENT	ACTION_ORIENTATION	ACTION_TIMING	ACTION_REFERENCE_OLD_TABLE	ACTION_REFERENCE_NEW_TABLE	ACTION_REFERENCE_OLD_ROW	ACTION_REFERENCE_NEW_ROW	CREATED	SQL_MODE	DEFINER	CHARACTER_SET_CLIENT	COLLATION_CONNECTION	DATABASE_COLLATION
select * from `information_schema`.`TRIGGERS` where `EVENT_OBJECT_TABLE` = NULL;
TRIGGER_CATALOG	TRIGGER_SCHEMA	TRIGGER_NAME	EVENT_MANIPULATION	EVENT_OBJECT_CATALOG	EVENT_OBJECT_SCHEMA	EVENT_OBJECT_TABLE	ACTION_ORDER	ACTION_CONDITION	ACTION_STATEMENT	ACTION_ORIENTATION	ACTION_TIMING	ACTION_REFERENCE_OLD_TABLE	ACTION_REFERENCE_NEW_TABLE	ACTION_REFERENCE_OLD_ROW	ACTION_REFERENCE_NEW_ROW	CREATED	SQL_MODE	DEFINER	CHARACTER_SET_CLIENT	COLLATION_CONNECTION	DATABASE_COLLATION
select * from `information_schema`.`VIEWS` where `TABLE_SCHEMA` = NULL;
TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	VIEW_DEFINITION	CHECK_OPTION	IS_UPDATABLE	DEFINER	SECURITY_TYPE	CHARACTER_SET_CLIENT	COLLATION_CONNECTION
select * from `information_schema`.`VIEWS` where `TABLE_NAME` = NULL;
TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	VIEW_DEFINITION	CHECK_OPTION	IS_UPDATABLE	DEFINER	SECURITY_TYPE	CHARACTER_SET_CLIENT	COLLATION_CONNECTION
explain extended select 1 from information_schema.TABLES;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	TABLES	ALL	NULL	NULL	NULL	NULL	NULL	NULL	Skip_open_table; Scanned all databases
Warnings:
Note	1003	select 1 AS `1` from `information_schema`.`TABLES`
End of 5.1 tests.