Commit 0806d9a8 authored by unknown's avatar unknown
Browse files

BUG#14553: NULL in WHERE resets LAST_INSERT_ID 

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.


mysql-test/r/odbc.result:
  test suite for the bug
mysql-test/r/rpl_insert_id.result:
  test for the fix in replication
mysql-test/t/odbc.test:
  test suite for the bug
mysql-test/t/rpl_insert_id.test:
  test for the fix in replication
sql/sql_class.cc:
  initialize the flag
sql/sql_class.h:
  flag's declaration and set code when setting the last_insert_id
sql/sql_select.cc:
  the special flag is used instead of last_insert_id
parent d388da98

mysql-test/r/odbc.result

+11 −0
Original line number Diff line number Diff line
@@ -14,3 +14,14 @@ explain select * from t1 where b is null; 
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra

1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables

drop table t1;

CREATE TABLE t1 (a INT AUTO_INCREMENT PRIMARY KEY);

INSERT INTO t1 VALUES (NULL);

SELECT sql_no_cache a, last_insert_id() FROM t1 WHERE a IS NULL;

a	last_insert_id()

1	1

SELECT sql_no_cache a, last_insert_id() FROM t1 WHERE a IS NULL;

a	last_insert_id()

SELECT sql_no_cache a, last_insert_id() FROM t1;

a	last_insert_id()

1	1

DROP TABLE t1;

mysql-test/r/rpl_insert_id.result

+14 −0
Original line number Diff line number Diff line
@@ -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;

mysql-test/t/odbc.test

+10 −0
Original line number Diff line number Diff line
@@ -21,4 +21,14 @@ select * from t1 where a is null; 
explain select * from t1 where b is null;

drop table t1;



#

# Bug #14553: NULL in WHERE resets LAST_INSERT_ID

#

CREATE TABLE t1 (a INT AUTO_INCREMENT PRIMARY KEY);

INSERT INTO t1 VALUES (NULL);

SELECT sql_no_cache a, last_insert_id() FROM t1 WHERE a IS NULL;

SELECT sql_no_cache a, last_insert_id() FROM t1 WHERE a IS NULL;

SELECT sql_no_cache a, last_insert_id() FROM t1;

DROP TABLE t1;



# End of 4.1 tests

mysql-test/t/rpl_insert_id.test

+19 −1
Original line number Diff line number Diff line
@@ -74,4 +74,22 @@ SET FOREIGN_KEY_CHECKS=0; 
INSERT INTO t1 VALUES (1),(1);

sync_slave_with_master;

 

#

# Bug#14553: NULL in WHERE resets LAST_INSERT_ID

#

connection master;

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;

sync_slave_with_master;

connection slave;

select * from t2;

connection master;

drop table t1;

drop table t2;

sync_slave_with_master;

# End of 4.1 tests

sql/sql_class.cc

+1 −0
Original line number Diff line number Diff line
@@ -265,6 +265,7 @@ THD::THD() 
    ulong tmp=sql_rnd_with_mutex();

    randominit(&rand, tmp + (ulong) &rand, tmp + (ulong) ::query_id);

  }

  substitute_null_with_insert_id = FALSE;

}