SELECT MIN(price) min, MAX(price) max, AVG(price) avg FROM (SELECT SUBSTRING( MAX(concat(date_,";",price)), 12) price FROM t1 WHERE itemid=128 AND grpid='rozn' GROUP BY itemid, grpid, vendor) lastprices;
Note 1003 select high_priority <in_optimizer>(0,<exists>(select 1 AS `Not_used` from test.t1 a where isnull(1) having <is_not_null_test>(1) limit 1)) AS `0 IN (SELECT 1 FROM t1 a)`
Note 1003 select high_priority <in_optimizer>(0,<exists>(select 1 AS `Not_used` from test.t1 a limit 1)) AS `0 IN (SELECT 1 FROM t1 a)`
INSERT INTO t1 (pseudo) VALUES ('test1');
SELECT 0 IN (SELECT 1 FROM t1 a);
0 IN (SELECT 1 FROM t1 a)
...
...
@@ -1170,9 +1170,9 @@ SELECT 0 IN (SELECT 1 FROM t1 a);
EXPLAIN EXTENDED SELECT 0 IN (SELECT 1 FROM t1 a);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY NULL NULL NULL NULL NULL NULL NULL No tables used
2 DEPENDENT SUBQUERY NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables
Note 1003 select high_priority <in_optimizer>(0,<exists>(select 1 AS `Not_used` from test.t1 a where isnull(1) having <is_not_null_test>(1) limit 1)) AS `0 IN (SELECT 1 FROM t1 a)`
Note 1003 select high_priority <in_optimizer>(0,<exists>(select 1 AS `Not_used` from test.t1 a limit 1)) AS `0 IN (SELECT 1 FROM t1 a)`
drop table t1;
CREATE TABLE `t1` (
`i` int(11) NOT NULL default '0',
...
...
@@ -1629,7 +1629,63 @@ insert into t1 values ('aaa'), ('bbb'),('eee'),('mmm'),('ppp');
select count(*) from t1 as w1 where w1.val in (select w2.val from t1 as w2 where w2.val like 'm%') and w1.val in (select w3.val from t1 as w3 where w3.val like 'e%');
count(*)
0
drop table if exists t1;
drop table t1;
create table t1 (id int not null, text varchar(20) not null default '', primary key (id));
select * from t1 where id not in (select id from t1 where id < 8);
id text
8 text8
9 text9
10 text10
11 text11
12 text12
select * from t1 as tt where not exists (select id from t1 where id < 8 and (id = tt.id or id is null) having id is not null);
id text
8 text8
9 text9
10 text10
11 text11
12 text12
explain extended select * from t1 where id not in (select id from t1 where id < 8);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t1 ALL NULL NULL NULL NULL 12 Using where
2 DEPENDENT SUBQUERY t1 unique_subquery PRIMARY PRIMARY 4 func 1 Using index; Using where
Warnings:
Note 1003 select high_priority test.t1.id AS `id`,test.t1.text AS `text` from test.t1 where not(<in_optimizer>(test.t1.id,<exists>(<primary_index_lookup>(<cache>(test.t1.id) in t1 on PRIMARY where (test.t1.id < 8)))))
explain extended select * from t1 as tt where not exists (select id from t1 where id < 8 and (id = tt.id or id is null) having id is not null);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY tt ALL NULL NULL NULL NULL 12 Using where
2 DEPENDENT SUBQUERY t1 eq_ref PRIMARY PRIMARY 4 test.tt.id 7 Using where; Using index
Warnings:
Note 1276 Field or reference 'tt.id' of SELECT #2 was resolved in SELECT #1
Note 1003 select high_priority test.tt.id AS `id`,test.tt.text AS `text` from test.t1 tt where not(exists(select test.t1.id AS `id` from test.t1 where ((test.t1.id < 8) and ((test.t1.id = test.tt.id) or isnull(test.t1.id))) having (test.t1.id is not null) limit 1))
insert into t1 (id, text) values (1000, 'text1000'), (1001, 'text1001');
create table t2 (id int not null, text varchar(20) not null default '', primary key (id));
select * from t1 a left join t2 b on (a.id=b.id or b.id is null) join t1 c on (if(isnull(b.id), 1000, b.id)=c.id);
id text id text id text
1 text1 1 text1 1 text1
2 text2 2 text2 2 text2
3 text3 3 text3 3 text3
4 text4 4 text4 4 text4
5 text5 5 text5 5 text5
6 text6 6 text6 6 text6
7 text7 7 text7 7 text7
8 text8 8 text8 8 text8
9 text9 9 text9 9 text9
10 text10 10 text10 10 text10
11 text11 11 text1 11 text11
12 text12 12 text2 12 text12
1000 text1000 NULL NULL 1000 text1000
1001 text1001 NULL NULL 1000 text1000
explain extended select * from t1 a left join t2 b on (a.id=b.id or b.id is null) join t1 c on (if(isnull(b.id), 1000, b.id)=c.id);
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE a ALL NULL NULL NULL NULL 14
1 SIMPLE b eq_ref PRIMARY PRIMARY 4 test.a.id 2
1 SIMPLE c eq_ref PRIMARY PRIMARY 4 func 1 Using where
Warnings:
Note 1003 select high_priority test.a.id AS `id`,test.a.text AS `text`,test.b.id AS `id`,test.b.text AS `text`,test.c.id AS `id`,test.c.text AS `text` from test.t1 a left join test.t2 b on(((test.a.id = test.b.id) or isnull(test.b.id))) join test.t1 c where (if(isnull(test.b.id),1000,test.b.id) = test.c.id)
drop table t1,t2;
create table t1 (a int);
insert into t1 values (1);
explain select benchmark(1000, (select a from t1 where a=sha(rand())));