Bug #6089 FOUND_ROWS returns wrong values when no table/view is used

• Submitted: 14 Oct 2004 10:45
• Modified: 2 Mar 2005 21:14
• Reporter: Georg Richter
• Status: Closed
• Category: MySQL Server
• Severity: S3 (Non-critical)
• Version: 4.1
• OS: Linux (Linux)
• Assigned to: Ramil Kalimullin
• CPU Architecture: Any

[14 Oct 2004 10:45] Georg Richter

Description:
See how to repeat 

How to repeat:
5.0.2-alpha-debug-log 
[12:40] root@test> SELECT SQL_CALC_FOUND_ROWS "foo" UNION SELECT "bar"; 
+-----+ 
| foo | 
+-----+ 
| foo | 
| bar | 
+-----+ 
2 rows in set (0.00 sec) 
 
5.0.2-alpha-debug-log 
[12:41] root@test> SELECT FOUND_ROWS(); 
+--------------+ 
| FOUND_ROWS() | 
+--------------+ 
|            2 | 
+--------------+ 
1 row in set (0.00 sec) 
 
5.0.2-alpha-debug-log 
[12:41] root@test> SELECT SQL_CALC_FOUND_ROWS "foo" UNION SELECT "bar" LIMIT 0; 
Empty set (0.00 sec) 
 
5.0.2-alpha-debug-log 
[12:42] root@test> SELECT FOUND_ROWS(); 
+--------------+ 
| FOUND_ROWS() | 
+--------------+ 
|            1 | 
+--------------+ 
1 row in set (0.00 sec) 
 
5.0.2-alpha-debug-log 
[12:42] root@test> 
5.0.2-alpha-debug-log 
[12:42] root@test> SELECT SQL_CALC_FOUND_ROWS 'foo'; 
+-----+ 
| foo | 
+-----+ 
| foo | 
+-----+ 
1 row in set (0.00 sec) 
 
5.0.2-alpha-debug-log 
[12:42] root@test> SELECT FOUND_ROWS(); 
+--------------+ 
| FOUND_ROWS() | 
+--------------+ 
|            0 | 
+--------------+ 
1 row in set (0.00 sec)

[14 Oct 2004 12:07] MySQL Verification Team

Verified with 4.1.6 and 5.0.2

[15 Oct 2004 23:23] Konstantin Osipov

I'm not sure if it's the same issue, or should be moved to a separate bug, but
if found_rows() is used in any non-trivial query, it always returns 0:

mysql> select * FROM t1 limit 1;
+------+
| a    |
+------+
|    1 |
+------+
1 row in set (0.00 sec)

mysql> select found_rows();
+--------------+
| found_rows() |
+--------------+
|            1 |
+--------------+
1 row in set (0.00 sec)

mysql> select * FROM t1 limit 1;
+------+
| a    |
+------+
|    1 |
+------+
1 row in set (0.00 sec)

mysql> select *, found_rows() from t1 limit 1;
+------+--------------+
| a    | found_rows() |
+------+--------------+
|    1 |            0 |
+------+--------------+
1 row in set (0.00 sec)

[1 Mar 2005 11:19] Ramil Kalimullin

fixed in 4.1.11

[2 Mar 2005 15:32] Konstantin Osipov

Reviewed additional patch to make the previos patch prepared-statements friendly.

[2 Mar 2005 21:14] Paul DuBois

Noted in 4.1.11 changelog.