Re: UPDATE with multiple WHERE conditions

On Wed, Jun 12, 2024 at 5:28 PM Rich Shepard <rshepard@appl-ecosys.com> wrote:

I have a table with 3492 rows. I want to update a boolean column from
'false' to 'true' for 295 rows based on the value of another column.

Is there a way to access a file with those condition values? If not, should
I create a temporary table with one column containing those values, or do I
write a psql script with 295 lines, one for each row to be updated?

A plain UPDATE might work.  

 

UPDATE to_be_updated a

SET bool_col = true

FROM other_table b

WHERE a.pk = b.pk

  AND b.field3 = mumble;

(You can join them, right?)

Add "begin;" to that and try it.  If you don't get exactly UPDATE 295 reported, then "rollback;";