I wish to concatenate all the results from TableB into a column in TableA, something like this.
UPDATE tableA SET column=CONCAT(
SELECT col FROM tableB WHERE tableA.key = tableB.keyA
)
So if table B is like this
| keyA | col |
|---|---|
| 1 | A |
| 1 | B |
| 1 | C |
After the operation, key 1 of tableA would look like this
| key | column |
|---|---|
| 1 | A B C |