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Fixed bug#19077: A nested materialized derived table is used before being populated.

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The convert_constant_item() function converts constant items to ints on
prepare phase to optimize execution speed. In this case it tries to evaluate
subselect which contains a derived table and is contained in a derived table. 
All derived tables are filled only after all derived tables are prepared.
So evaluation of subselect with derived table at the prepare phase will
return a wrong result.

A new flag with_subselect is added to the Item class. It indicates that
expression which this item represents is a subselect or contains a subselect.
It is set to 0 by default. It is set to 1 in the Item_subselect constructor
for subselects.
For Item_func and Item_cond derived classes it is set after fixing any argument
in Item_func::fix_fields() and Item_cond::fix_fields accordingly.
The convert_constant_item() function now doesn't convert a constant item
if the with_subselect flag set in it.
This commit is contained in:
evgen@moonbone.local
2006-05-18 00:55:28 +04:00
parent 1e6c14d687
commit 1d820585ae
9 changed files with 65 additions and 5 deletions
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9
mysql-test/r/view.result
View File

@@ -2660,3 +2660,12 @@ SELECT * FROM v1;
id t COUNT(*)
DROP VIEW v1;
DROP TABLE t1;
CREATE TABLE t1 (i INT, j BIGINT);
INSERT INTO t1 VALUES (1, 2), (2, 2), (3, 2);
CREATE VIEW v1 AS SELECT MIN(j) AS j FROM t1;
CREATE VIEW v2 AS SELECT MIN(i) FROM t1 WHERE j = ( SELECT * FROM v1 );
SELECT * FROM v2;
MIN(i)
1
DROP VIEW v2, v1;
DROP TABLE t1;