Question

I have a MySQL query that I would like to enhance by requiring that all values of client.client_name are printed out in the result, even if no values are found for every row in that table. The current table shows:

client.client_name
Client A
Client B
Client C

The current MySQL query is below:

    SELECT X.expr1 AS 'Project Name', SUM(X.expr2) AS 'Total Hours Logged', X.expr3 - sum(X.expr2) AS 'Monthly Hours Remaining', X.expr4 AS 'Last Day', DATEDIFF(X.expr4 , curdate()) AS 'Days Remaining'
FROM 
(SELECT 
    client.client_name AS expr1
    , sum(time_records.value) AS expr2
    , client.monthly_hours AS expr3
FROM project_objects
  INNER JOIN projects
    ON projects.id = project_objects.project_id
  INNER JOIN time_records
    ON time_records.parent_id = project_objects.id
  LEFT JOIN client  
  ON project_objects.project_id = client.project_id 
  WHERE time_records.parent_type = 'Task' 
  AND client.start_day_of_month < dayofmonth(curdate())
  AND time_records.state = 3
  GROUP BY client.client_name

  UNION

  SELECT 
    client.client_name AS expr1
    , sum(time_records.value) as expr2
    , client.monthly_hours AS expr3
  FROM projects
  INNER JOIN time_records
    ON projects.id = time_records.parent_id
  LEFT JOIN client  
   ON projects.id = client.project_id 
  WHERE time_records.parent_type = 'Project'
  AND client.start_day_of_month < dayofmonth(curdate())
  AND time_records.state = 3
  GROUP BY client.client_name
) X
GROUP BY X.expr1
ORDER BY DATEDIFF(X.expr4 , curdate()

As you can see from the above query – I added a Left Join for the client table, however it doesn’t result in printing out all client records – it only prints those for which there are time_records available. I think this is related to the nesting or the order of how I am writing the joins, but can’t seem to figure it out. If you have any ideas it would be greatly appreciated. Thanks!

Answer 1

Please try order as below:

FROM client LEFT JOIN project_objects 
    ON project_objects.project_id = client.project_id 

see SQLFiddle for the final solution here: http://sqlfiddle.com/#!2/30362/16