Description:
In this page :
<http://www.mysql.com/doc/en/Miscellaneous_functions.html#IDX1367>
We can read :
"Returns the number of rows that the preceding SELECT SQL_CALC_FOUND_ROWS ... command would have returned, if it had not been restricted with LIMIT."
But FOUND_ROWS() seems to return the number of "rows that the preceding SELECT SQL_CALC_FOUND_ROWS ... command would have returned, if it had not been restricted with LIMIT" if the preceding SELECT contain SQL_CALC_FOUND_ROWS, but if the preceding SELECT doesn't contain SQL_CALC_FOUND_ROWS, FOUND_ROWS() return the number of rows returned by this preceding SELECT.
How to repeat:
-- Creating and populating the table --
CREATE TABLE `test_table` (
`test_field` VARCHAR( 10 ) NOT NULL
);
ALTER TABLE `test_table` DROP PRIMARY KEY ,
ADD PRIMARY KEY ( `test_field` )
INSERT INTO `test_table` ( `test_field` )
VALUES (
'alpha'
);
INSERT INTO `test_table` ( `test_field` )
VALUES (
'bravo'
);
INSERT INTO `test_table` ( `test_field` )
VALUES (
'tango'
);
-- This is the interactive section with mysql --
mysql> SELECT SQL_CALC_FOUND_ROWS test_field FROM test_table LIMIT 1;
+------------+
| test_field |
+------------+
| alpha |
+------------+
1 row in set (0.00 sec)
mysql> SELECT FOUND_ROWS();
+--------------+
| FOUND_ROWS() |
+--------------+
| 3 |
+--------------+
1 row in set (0.00 sec)
mysql> SELECT test_field FROM test_table LIMIT 2;
+------------+
| test_field |
+------------+
| alpha |
| bravo |
+------------+
2 rows in set (0.00 sec)
mysql> SELECT FOUND_ROWS();
+--------------+
| FOUND_ROWS() |
+--------------+
| 2 |
+--------------+
1 row in set (0.00 sec)
mysql> SELECT test_field FROM test_table;
+------------+
| test_field |
+------------+
| alpha |
| bravo |
| tango |
+------------+
3 rows in set (0.00 sec)
mysql> SELECT FOUND_ROWS();
+--------------+
| FOUND_ROWS() |
+--------------+
| 3 |
+--------------+
1 row in set (0.00 sec)
Suggested fix:
Be more precise on the documentation, or, if the documentation is right, changing the FOUND_ROWS() behavior : he keep the result from the preceding SELECT SQL_CALC_FOUND_ROWS.
