Bug#24562 (ALTER TABLE ... ORDER BY ... with complex expression asserts)

WL#3681 (ALTER TABLE ORDER BY)

Before this fix, the ALTER TABLE statement implemented an ORDER BY option
with the following characteristics :

1) The order by clause accepts a list of criteria, with optional ASC or
DESC keywords

2) Each criteria can be a general expression, involving operators,
native functions, stored functions, user defined functions, subselects ...

With this fix :

1) has been left unchanged, since it's a de-facto existing feature,
that was already present in the code base and partially covered in the test
suite. Code coverage for ASC and DESC was missing and has been improved.

2) has been changed to limit the kind of criteria that are permissible:
now only a column name is valid.


mysql-test/r/alter_table.result:
  Prevent ALTER TABLE ORDER BY clauses to use general expressions.
mysql-test/t/alter_table.test:
  Prevent ALTER TABLE ORDER BY clauses to use general expressions.
sql/sql_yacc.yy:
  Prevent ALTER TABLE ORDER BY clauses to use general expressions.

mysql-test/r/alter_table.result

@@ -690,3 +690,116 @@ SHOW INDEX FROM bug24219_2;
 Table	Non_unique	Key_name	Seq_in_index	Column_name	Collation	Cardinality	Sub_part	Packed	Null	Index_type	Comment
 bug24219_2	1	a	1	a	A	NULL	NULL	NULL	YES	BTREE	disabled
 DROP TABLE bug24219_2;
+drop table if exists table_24562;
+create table table_24562(
+section int,
+subsection int,
+title varchar(50));
+insert into table_24562 values
+(1, 0, "Introduction"),
+(1, 1, "Authors"),
+(1, 2, "Acknowledgements"),
+(2, 0, "Basics"),
+(2, 1, "Syntax"),
+(2, 2, "Client"),
+(2, 3, "Server"),
+(3, 0, "Intermediate"),
+(3, 1, "Complex queries"),
+(3, 2, "Stored Procedures"),
+(3, 3, "Stored Functions"),
+(4, 0, "Advanced"),
+(4, 1, "Replication"),
+(4, 2, "Load balancing"),
+(4, 3, "High availability"),
+(5, 0, "Conclusion");
+select * from table_24562;
+section	subsection	title
+1	0	Introduction
+1	1	Authors
+1	2	Acknowledgements
+2	0	Basics
+2	1	Syntax
+2	2	Client
+2	3	Server
+3	0	Intermediate
+3	1	Complex queries
+3	2	Stored Procedures
+3	3	Stored Functions
+4	0	Advanced
+4	1	Replication
+4	2	Load balancing
+4	3	High availability
+5	0	Conclusion
+alter table table_24562 add column reviewer varchar(20),
+order by title;
+select * from table_24562;
+section	subsection	title	reviewer
+1	2	Acknowledgements	NULL
+4	0	Advanced	NULL
+1	1	Authors	NULL
+2	0	Basics	NULL
+2	2	Client	NULL
+3	1	Complex queries	NULL
+5	0	Conclusion	NULL
+4	3	High availability	NULL
+3	0	Intermediate	NULL
+1	0	Introduction	NULL
+4	2	Load balancing	NULL
+4	1	Replication	NULL
+2	3	Server	NULL
+3	3	Stored Functions	NULL
+3	2	Stored Procedures	NULL
+2	1	Syntax	NULL
+update table_24562 set reviewer="Me" where section=2;
+update table_24562 set reviewer="You" where section=3;
+alter table table_24562
+order by section ASC, subsection DESC;
+select * from table_24562;
+section	subsection	title	reviewer
+1	2	Acknowledgements	NULL
+1	1	Authors	NULL
+1	0	Introduction	NULL
+2	3	Server	Me
+2	2	Client	Me
+2	1	Syntax	Me
+2	0	Basics	Me
+3	3	Stored Functions	You
+3	2	Stored Procedures	You
+3	1	Complex queries	You
+3	0	Intermediate	You
+4	3	High availability	NULL
+4	2	Load balancing	NULL
+4	1	Replication	NULL
+4	0	Advanced	NULL
+5	0	Conclusion	NULL
+alter table table_24562
+order by table_24562.subsection ASC, table_24562.section DESC;
+select * from table_24562;
+section	subsection	title	reviewer
+5	0	Conclusion	NULL
+4	0	Advanced	NULL
+3	0	Intermediate	You
+2	0	Basics	Me
+1	0	Introduction	NULL
+4	1	Replication	NULL
+3	1	Complex queries	You
+2	1	Syntax	Me
+1	1	Authors	NULL
+4	2	Load balancing	NULL
+3	2	Stored Procedures	You
+2	2	Client	Me
+1	2	Acknowledgements	NULL
+4	3	High availability	NULL
+3	3	Stored Functions	You
+2	3	Server	Me
+alter table table_24562 order by 12;
+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 '12' at line 1
+alter table table_24562 order by (section + 12);
+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 '(section + 12)' at line 1
+alter table table_24562 order by length(title);
+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 'length(title)' at line 1
+alter table table_24562 order by (select 12 from dual);
+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 '(select 12 from dual)' at line 1
+alter table table_24562 order by no_such_col;
+ERROR 42S22: Unknown column 'no_such_col' in 'order clause'
+drop table table_24562;

mysql-test/t/alter_table.test

@@ -518,4 +518,70 @@ SHOW INDEX FROM bug24219_2;
 
 DROP TABLE bug24219_2;
 
+#
+# Bug#24562 (ALTER TABLE ... ORDER BY ... with complex expression asserts)
+#
+
+--disable_warnings
+drop table if exists table_24562;
+--enable_warnings
+
+create table table_24562(
+  section int,
+  subsection int,
+  title varchar(50));
+
+insert into table_24562 values
+(1, 0, "Introduction"),
+(1, 1, "Authors"),
+(1, 2, "Acknowledgements"),
+(2, 0, "Basics"),
+(2, 1, "Syntax"),
+(2, 2, "Client"),
+(2, 3, "Server"),
+(3, 0, "Intermediate"),
+(3, 1, "Complex queries"),
+(3, 2, "Stored Procedures"),
+(3, 3, "Stored Functions"),
+(4, 0, "Advanced"),
+(4, 1, "Replication"),
+(4, 2, "Load balancing"),
+(4, 3, "High availability"),
+(5, 0, "Conclusion");
+
+select * from table_24562;
+
+alter table table_24562 add column reviewer varchar(20),
+order by title;
+
+select * from table_24562;
+
+update table_24562 set reviewer="Me" where section=2;
+update table_24562 set reviewer="You" where section=3;
+
+alter table table_24562
+order by section ASC, subsection DESC;
+
+select * from table_24562;
+
+alter table table_24562
+order by table_24562.subsection ASC, table_24562.section DESC;
+
+select * from table_24562;
+
+--error 1064
+alter table table_24562 order by 12;
+--error 1064
+alter table table_24562 order by (section + 12);
+--error 1064
+alter table table_24562 order by length(title);
+--error 1064
+alter table table_24562 order by (select 12 from dual);
+
+--error 1054
+alter table table_24562 order by no_such_col;
+
+drop table table_24562;
+
 # End of 4.1 tests
+

sql/sql_yacc.yy

@@ -2021,7 +2021,7 @@ alter_list_item:
 	    lex->alter_info.is_simple= 0; 
 	    lex->alter_info.flags|= ALTER_OPTIONS;
 	  }
-	| order_clause         
+	| alter_order_clause
 	  {
 	    LEX *lex=Lex;
 	    lex->alter_info.is_simple= 0; 
@@ -3780,6 +3780,29 @@ olap_opt:
 	  }
 	;
 
+/*
+  Order by statement in ALTER TABLE
+*/
+
+alter_order_clause:
+          ORDER_SYM BY alter_order_list
+        ;
+
+alter_order_list:
+          alter_order_list ',' alter_order_item
+        | alter_order_item
+        ;
+
+alter_order_item:
+          simple_ident order_dir
+          {
+            THD *thd= YYTHD;
+            bool ascending= ($2 == 1) ? true : false;
+            if (add_order_to_list(thd, $1, ascending))
+              YYABORT;
+          }
+        ;
+
 /*
    Order by statement in select
 */