Question

The following mysql query…

SELECT a.*, b.*,
       ( 
            SELECT COUNT( * ) 
            FROM lp_units c 
            WHERE c.property_id = a.property_id 
        ) AS unitcount
FROM lp_property a,
     lp_property_confidential b
WHERE a.property_id = b.property_id
AND c.unitcount<= a.no_of_units
AND a.account_id = '1'

returns an error…

Unknown column 'c.unitcount' in 'where clause'

I think my query would be understandable. solve it to run….

Thanks in advance…

Answer 1

Don’t use c.unitcount. Just unitcount. unitcount is not a column of c but rather of the temporary table generated by the subquery.

However, this query is probably better written as a join anyway.

Try this query

SELECT
  a.*,
  b.*,
  COUNT(c.property_id) as unitcount
  FROM lp_property a
  JOIN lp_property_confidential b ON a.property_id = b.property_id
  JOIN lp_units c ON c.property_id = a.property_id
  WHERE
  a.account_id = '1'
  GROUP BY a.property_id
  HAVING unitcount <= a.no_of_units