MySQL left join subquery fail

Question

Following query runs well in MySQL 5.x

SELECT
  m_area.id, m_area.cn_areaName, m_area.de_areaName,
  m_area.en_areaName,m_area.jp_areaName,t_shop.count
FROM
  m_area left join   
(
select t_shop.areaID, count(areaID) AS count
from t_shop
group by t_shop.areaID
) t_shop
on m_area.id = t_shop.areaID

However, when I have to run it in a 4.0.23 MySQL DB with same DB structure and data it just return following message:

1064 - You have an error in your SQL syntax. Check the manual that corresponds to your MySQL server version for the right syntax to use near '[

  select t_shop.areaID, count(areaID) AS count from t_s 

I tried many times but still failed. Is left join to subquery not allowed in MySQL 4.x ? Then that mean I have to do it with a temp table?

Thanks in advance!

Answer 1

Subqueries were quite not well supported with MySQL 4.0 : it became possible to use them (at least, in some real, useful way) with MySQL 4.1 -- and MySQL 4.0 is really old, now...

See for instance this page of the MySQL manual : 12.2.8. Subquery Syntax (quoting, emphasis mine) :

Starting with MySQL 4.1 , all subquery forms and operations that the SQL standard requires are supported, as well as a few features that are MySQL-specific.

With MySQL versions prior to 4.1, it was necessary to work around or avoid the use of subqueries .
In many cases, subqueries can successfully be rewritten using joins and other methods. See Section 12.2.8.11, “Rewriting Subqueries as Joins for Earlier MySQL Versions” .

Answer 2

Only thing I could think of is adding the tablename to your areaID in the subquery or renaming the reserved word count to cnt.

SELECT  m_area.id
        , m_area.cn_areaName
        , m_area.de_areaName
        , m_area.en_areaName
        ,m_area.jp_areaName
        ,t_shop.cnt
FROM     m_area 
        left join ( 
          select     t_shop.areaID
                    , count(t_shop.areaID) AS cnt 
          from       t_shop 
          group by   t_shop.areaID 
        ) t_shop on m_area.id = t_shop.areaID 

Answer 3

take out ", count(areaID) AS count"

The multiple columns in the subquery is messing up the join.

A temp table should work fine ....

Have fun!