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BUG#14553: NULL in WHERE resets LAST_INSERT_ID

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To make MySQL compatible with some ODBC applications, you can find
the AUTO_INCREMENT value for the last inserted row with the following query:
 SELECT * FROM tbl_name WHERE auto_col IS NULL.
This is done with a special code that replaces 'auto_col IS NULL' with
'auto_col = LAST_INSERT_ID'.
However this also resets the LAST_INSERT_ID to 0 as it uses it for a flag
so as to ensure that only the first SELECT ... WHERE auto_col IS NULL
after an INSERT has this special behaviour.
In order to avoid resetting the LAST_INSERT_ID a special flag is introduced
in the THD class. This flag is used to restrict the second and subsequent
SELECTs instead of LAST_INSERT_ID.
This commit is contained in:
gkodinov/kgeorge@mysql.com/rakia.(none)
2006-07-10 16:27:03 +03:00
parent ab440799e1
commit 2c9f5cc706
7 changed files with 60 additions and 3 deletions
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14
mysql-test/r/rpl_insert_id.result
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@ -73,3 +73,17 @@ CREATE TABLE t1 ( a INT UNIQUE );
SET FOREIGN_KEY_CHECKS=0;
INSERT INTO t1 VALUES (1),(1);
ERROR 23000: Duplicate entry '1' for key 1
drop table t1;
create table t1(a int auto_increment, key(a));
create table t2(a int);
insert into t1 (a) values (null);
insert into t2 (a) select a from t1 where a is null;
insert into t2 (a) select a from t1 where a is null;
select * from t2;
a
1
select * from t2;
a
1
drop table t1;
drop table t2;