Question

I need to delete from two tables, based on a query in one table

Table: entities
guid: integer
subtype: integer
time_created: integer (Unix timestamp)

Table: objects_entity
guid: integer
title: text

guid in objects_entity is a foreign key to entities.guid

I need to delete related records in both tables based on subtype=17 and time_created is older than 14 days in entities (so also delete related objects_entity)

I’m very bad at SQL and by looking at examples I’ve created this:

DELETE entities, objects_entity FROM entities a INNER JOIN objects_entity b on b.guid = a.guid AND a.subtype =17 AND a.time_created < UNIX_TIMESTAMP(DATE_SUB(NOW(), INTERVAL 14 DAY))

but this gives the error:

#1109 - Unknown table 'entities' in MULTI DELETE

which is beyond me, as a select statement identical to above works correctly…. The table exists.

Any ideas what’s wrong with my syntax? Many thanks.

Answer 1

You need to replace

DELETE entities, objects_entity

with

DELETE a, b

since you are aliasing your tables with a and b.