SQL UPDATE all values in a field with appended string CONCAT not working
Here is what I want to do:
current table:
+----+-------------+
| id | data |
+----+-------------+
| 1 | max |
| 2 | linda |
| 3 | sam |
| 4 | henry |
+----+-------------+
Mystery Query ( something like "UPDATE table SET data = CONCAT(data, 'a')"
)
resulting table:
+----+-------------+
| id | data |
+----+-------------+
| 1 | maxa |
| 2 | lindaa |
| 3 | sama |
| 4 | henrya |
+----+-------------+
thats it! I just need to do it in a single query, but can't seem to find a way. I am using mySQL on bluehost (I think its version 4.1)
Thanks everyone.
Solution 1:
That's pretty much all you need:
mysql> select * from t;
+------+-------+
| id | data |
+------+-------+
| 1 | max |
| 2 | linda |
| 3 | sam |
| 4 | henry |
+------+-------+
4 rows in set (0.02 sec)
mysql> update t set data=concat(data, 'a');
Query OK, 4 rows affected (0.01 sec)
Rows matched: 4 Changed: 4 Warnings: 0
mysql> select * from t;
+------+--------+
| id | data |
+------+--------+
| 1 | maxa |
| 2 | lindaa |
| 3 | sama |
| 4 | henrya |
+------+--------+
4 rows in set (0.00 sec)
Not sure why you'd be having trouble, though I am testing this on 5.1.41
Solution 2:
CONCAT with a null value returns null, so the easiest solution is:
UPDATE myTable SET spares = IFNULL (CONCAT( spares , "string" ), "string")
Solution 3:
convert the NULL
values with empty string by wrapping it in COALESCE
"UPDATE table SET data = CONCAT(COALESCE(`data`,''), 'a')"
OR
Use CONCAT_WS instead:
"UPDATE table SET data = CONCAT_WS(',',data, 'a')"