Question

In a query I am using I am creating a temporary table. This is the query:

SELECT u1.url,u1.id,u1.domain FROM urls u1 JOIN 
(create new table here) u2 ON u1.id = u2.url_id 
GROUP BY u1.domain;

And right before this query I lock two tables:

LOCK TABLES urls WRITE, ips WRITE;

However, mysql gives me this error when I run my script:

Table 'u1' was not locked with LOCK TABLES

So can someone help me understand what I am doing wrong here? I don’t think I can declare u2 ahead of time, because it’s not really made yet.

Answer 1

I found the solution here:

LOCK TABLES urls WRITE, urls as u1 WRITE, ips WRITE;

Essentially if you’re going to reference a table with an alias after a lock statement, you need to lock it with an alias.