MySql计算日期行中包含（NULL）和'0000-00-00'值的所有元组

Question

i want to count all those rows from mysql table where in the "where clause" three columns having two possible values in it. ie ( NULL ) and OR 0000-00-00 . For this i have written the following sql which returns a result where i am not sure it is a perfect sql query or not. Please guide me if i am doing wrong.

      SELECT 
          COUNT(sno) AS totalCases 
      FROM
         myTable
       WHERE (dateOfTransferInstituion IS NULL OR dateOfTransferInstituion = '0000-00-00')
         AND 
             (date_remanded IS NULL OR date_remanded = '0000-00-00')
         AND 
             (date_restored IS NULL OR date_restored = '0000-00-00')

Thanks in advance.

Answer 1

I have read your task and I think your query is correct, but it is possible to do it more elegantly, like this :

  SELECT 
      COUNT(sno) AS totalCases 
  FROM
     myTable
   WHERE IFNULL(dateOfTransferInstituion,'0000-00-00') = '0000-00-00'
     AND 
         IFNULL(date_remanded,'0000-00-00') = '0000-00-00'
     AND 
         IFNULL(date_restored,'0000-00-00') = '0000-00-00'