How do you use the “WITH” clause in MySQL?

Question

I am converting all my SQL Server queries to MySQL and my queries that have WITH in them are all failing. Here\'s an example:

WITH t1 AS
(
              


        

Answer 1

MySQL prior to version 8.0 doesn't support the WITH clause (CTE in SQL Server parlance; Subquery Factoring in Oracle), so you are left with using:

• TEMPORARY tables
• DERIVED tables
• inline views (effectively what the WITH clause represents - they are interchangeable)

The request for the feature dates back to 2006.

As mentioned, you provided a poor example - there's no need to perform a subselect if you aren't altering the output of the columns in any way:

  SELECT * 
    FROM ARTICLE t
    JOIN USERINFO ui ON ui.user_userid = t.article_ownerid
    JOIN CATEGORY c ON c.catid =  t.article_categoryid
   WHERE t.published_ind = 0
ORDER BY t.article_date DESC 
   LIMIT 1, 3

Here's a better example:

SELECT t.name,
       t.num
  FROM TABLE t
  JOIN (SELECT c.id
               COUNT(*) 'num'
          FROM TABLE c
         WHERE c.column = 'a'
      GROUP BY c.id) ta ON ta.id = t.id