VJ wrote:
I am no guru, but I carried out the following test
mysql> select * from t;
+------+-------+
| c1 | c2 |
+------+-------+
| 1 | hello |
| 2 | hello |
| 3 | NULL |
| 4 | NULL |
| 5 | Helly |
| 6 | Nelly |
| 7 | Kelly |
+------+-------+
7 rows in set (0.00 sec)
mysql> update t set c2 = replace(t2,'hell', 'heaven');
ERROR 1054: Unknown column 't2' in 'field list'
mysql> update t set c2 = replace(c2,'hell', 'heaven');
Query OK, 2 rows affected (0.00 sec)
Rows matched: 7 Changed: 2 Warnings: 0
mysql> select * from t;
+------+---------+
| c1 | c2 |
+------+---------+
| 1 | heaveno |
| 2 | heaveno |
| 3 | NULL |
| 4 | NULL |
| 5 | Helly |
| 6 | Nelly |
| 7 | Kelly |
+------+---------+
7 rows in set (0.01 sec)
The update statement found 7 rows (all of the rows in my table bcos
there was no where clause, and only two rows actually got updated.
Regards from VJ
I'm no MySQL guru, but I /do/ work with PostgreSQL. And SQL is SQL.
I think Row 5 didn't get an update because an UPDATE <column> SET <old>
TO <new> WHERE <condition> command is case-sensitive. "Hell" and "hell"
are two different character sequences.
Temlakos
