SQL Query to concatenate column values from multiple rows in Oracle
oracle, sql, string-aggregation
Solution
There are a few ways depending on what version you have - see the oracle documentation on string aggregation techniques. A very common one is to use `LISTAGG`:
SELECT pid, LISTAGG(Desc, ' ') WITHIN GROUP (ORDER BY seq) AS description
FROM B GROUP BY pid;
Then join to `A` to pick out the `pids` you want.
Note: Out of the box, `LISTAGG` only works correctly with `VARCHAR2` columns.
Problem
Would it be possible to construct SQL to concatenate column values from multiple rows? The following is an example: Table A ``` PID A B C ``` Table B ``` PID SEQ Desc A 1 Have A 2 a nice A 3 day. B 1 Nice Work. C 1 Yes C 2 we can C 3 do C 4 this work! ``` Output of the SQL should be - ``` PID Desc A Have a nice day. B Nice Work. C Yes we can do this work! ``` So basically the Desc column for out put table is a concatenation of the SEQ values from Table B? Any help with the SQL?