Question

So I have a two quesies that the first one select an array based on the $_SESSION and then is used in the second select.

My problem is that when I have for example for one use one entrie every thing is ok the table will be like this:

|DATA| USER1|
|DATA| USER2|
|DATA| USER3|

But if I have to entries for the same user I got duplicate like this:

|DATA| USER1| [1]
|DATA| USER1| [2]
|DATA| USER2|
|DATA| USER3|
|DATA| USER1| DUPLICATE of FIRST ENTRY USER ABOVE [1]
|DATA| USER1| DUPLICATE OF SECOND ENTRY USER ABOVE [2]

My code looks like this :

function make_table($user_id){
   first_query with this select `Select U.user_id
                                   from users U, tasks T
                                  where T.assigned_to = U.user_id 
                                    and T.status='Assigned'
                                    and U.parent_id = $_SESSION[userid]`;

  foreach ($query_result_worker as $row){
            $user_id_worker = $row['user_id'];

  //second_query with this select 

    SELECT T.task_id, T.job_server_id, T.TIMESTAMP, TT.task_type_name, T.STATUS,
           UO.username AS customer_name, UO.user_id AS customer_id, T.STATUS, T.quantity,
           T.order_id, U.username, T.priority, T.assigned_time, U.username, O.order_id
     FROM task_type TT, orders O, users UO, task_assignment T
     LEFT JOIN users U
        ON T.assigned_to = U.user_id
     WHERE T.task_type_id = TT.task_type_id
        AND O.order_id = T.order_id
        AND O.user_id = UO.user_id
        AND T.STATUS = 'Assigned'
        AND T.assigned_to = $ROW [user_id]
        AND T.TIMESTAMP <= CURRENT_TIMESTAMP
     ORDER BY T.priority DESC, DATE (T.TIMESTAMP), T.quantity DESC, T.task_id

    foreach ($result as $tablerow) {
    make the printing table stuff

     }
}

So I don’t know why it’s duplicating when I got two entries, any help please?

PS: if I have 3 entries for the same user it will be 6 for the same user, duplicates too.

Answer 1

Try adding DISTINCT to your first query:

SELECT DISTINCT U.user_id
FROM
    users U,
    tasks T
WHERE
    T.assigned_to = U.user_id
    AND T.status='Assigned'
    AND U.parent_id = $_SESSION[userid];

Also, I would avoid using implicit joins, especially when mixing them with explicit outer joins. It makes the query a bit harder to read, and (IMO) easier to make a mistake. Use the INNER JOIN syntax instead.

Your second query would look more like this:

SELECT
    T.task_id,
    T.job_server_id,
    T.TIMESTAMP,
    TT.task_type_name,
    T.STATUS,
    UO.username AS customer_name,
    UO.user_id AS customer_id,
    T.STATUS,
    T.quantity,
    T.order_id,
    U.username,
    T.priority,
    T.assigned_time,
    U.username,
    O.order_id
FROM
    task_type TT
    INNER JOIN task_assignment T
        ON T.task_type_id = TT.task_type_id
    INNER JOIN orders O
        ON O.order_id = T.order_id
    INNER JOIN users UO
        ON UO.user_id = O.user_id
    LEFT JOIN users U
        ON T.assigned_to = U.user_id
WHERE
    T.STATUS = 'Assigned'
    AND T.assigned_to = $ROW[user_id]
    AND T.TIMESTAMP <= CURRENT_TIMESTAMP
ORDER BY
    T.priority DESC,
    DATE(T.TIMESTAMP),
    T.quantity DESC,
    T.task_id