Commit a13fa8f6 authored by unknown's avatar unknown
Browse files

Merge epotemkin@bk-internal.mysql.com:/home/bk/mysql-5.0-opt 

into  moonbone.local:/home/evgen/bk-trees/mysql-5.0-opt


mysql-test/t/subselect.test:
  Auto merged
sql/item_subselect.cc:
  Auto merged
parents 2aa36d2d 2f78d5ca

mysql-test/r/ps.result

+15 −0
Original line number Diff line number Diff line
@@ -1514,4 +1514,19 @@ Variable_name Value 
Slow_queries	1

deallocate prepare no_index;

deallocate prepare sq;

CREATE TABLE t1 (a int);

INSERT INTO t1 VALUES (1), (2);

CREATE TABLE t2 (b int);

INSERT INTO t2 VALUES (NULL);

SELECT a FROM t1 WHERE (SELECT b FROM t2) IS NULL;

a

1

2

PREPARE stmt FROM 'SELECT a FROM t1 WHERE (SELECT b FROM t2) IS NULL';

EXECUTE stmt;

a

1

2

DEALLOCATE PREPARE stmt;

DROP TABLE t1,t2;

End of 5.0 tests.

mysql-test/r/subselect.result

+13 −0
Original line number Diff line number Diff line
@@ -3033,6 +3033,19 @@ t3 CREATE TABLE `t3` ( 
  `a` datetime default NULL

) ENGINE=MyISAM DEFAULT CHARSET=latin1

DROP TABLE t1,t2,t3;

CREATE TABLE t1 (a int);

INSERT INTO t1 VALUES (1), (2);

SELECT a FROM t1 WHERE (SELECT 1 FROM DUAL WHERE 1=0) > 0;

a

SELECT a FROM t1 WHERE (SELECT 1 FROM DUAL WHERE 1=0) IS NULL;

a

1

2

EXPLAIN SELECT a FROM t1 WHERE (SELECT 1 FROM DUAL WHERE 1=0) IS NULL;

id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra

1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	

2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE

DROP TABLE t1;

create table t1 (df decimal(5,1));

insert into t1 values(1.1);

insert into t1 values(2.2);

mysql-test/t/ps.test

+18 −0
Original line number Diff line number Diff line
@@ -1563,4 +1563,22 @@ execute sq; 
deallocate prepare no_index;

deallocate prepare sq;



#

# Bug 25027: query with a single-row non-correlated subquery

#            and IS NULL predicate

#



CREATE TABLE t1 (a int);

INSERT INTO t1 VALUES (1), (2);

CREATE TABLE t2 (b int);

INSERT INTO t2 VALUES (NULL);



SELECT a FROM t1 WHERE (SELECT b FROM t2) IS NULL;

PREPARE stmt FROM 'SELECT a FROM t1 WHERE (SELECT b FROM t2) IS NULL';



EXECUTE stmt;



DEALLOCATE PREPARE stmt;

DROP TABLE t1,t2;



--echo End of 5.0 tests.

mysql-test/t/subselect.test

+12 −0
Original line number Diff line number Diff line
@@ -1988,6 +1988,18 @@ SHOW CREATE TABLE t3; 


DROP TABLE t1,t2,t3;



#

# Bug 24670: subquery witout tables but with a WHERE clause

#



CREATE TABLE t1 (a int);

INSERT INTO t1 VALUES (1), (2);



SELECT a FROM t1 WHERE (SELECT 1 FROM DUAL WHERE 1=0) > 0;

SELECT a FROM t1 WHERE (SELECT 1 FROM DUAL WHERE 1=0) IS NULL;

EXPLAIN SELECT a FROM t1 WHERE (SELECT 1 FROM DUAL WHERE 1=0) IS NULL;



DROP TABLE t1;

# End of 4.1 tests



#

sql/item_subselect.cc

+17 −2
Original line number Diff line number Diff line
@@ -349,6 +349,7 @@ Item_singlerow_subselect::select_transformer(JOIN *join) 
      */

      !(select_lex->item_list.head()->type() == FIELD_ITEM ||

	select_lex->item_list.head()->type() == REF_ITEM) &&

      !join->conds && !join->having &&

      /*

        switch off this optimization for prepare statement,

        because we do not rollback this changes
@@ -373,8 +374,6 @@ Item_singlerow_subselect::select_transformer(JOIN *join) 
    */

    substitution->walk(&Item::remove_dependence_processor,

		       (byte *) select_lex->outer_select());

    /* SELECT without FROM clause can't have WHERE or HAVING clause */

    DBUG_ASSERT(join->conds == 0 && join->having == 0);

    return RES_REDUCE;

  }

  return RES_OK;
@@ -2277,6 +2276,22 @@ bool subselect_single_select_engine::no_tables() 
}





/*

  Check statically whether the subquery can return NULL



  SINOPSYS

    subselect_single_select_engine::may_be_null()



  RETURN

    FALSE  can guarantee that the subquery never return NULL

    TRUE   otherwise

*/

bool subselect_single_select_engine::may_be_null()

{

  return ((no_tables() && !join->conds && !join->having) ? maybe_null : 1);

}





/*

  Report about presence of tables in subquery