Question

I have a table that stores data on days of the week. I’m wanting to return a row for each day of the week even if there isn’t any rows for that day of the week in my table. Here’s my current sql select statement.

SELECT StoreID,
   CASE 
       WHEN S.[DayOfWeek] = 1 THEN 'Sunday' 
       WHEN S.[DayOfWeek] = 2 THEN 'Monday'
       WHEN S.[DayOfWeek] = 3 THEN 'Tuesday'
       WHEN S.[DayOfWeek] = 4 THEN 'Wednesday'
       WHEN S.[DayOfWeek] = 5 THEN 'Thursday'
       WHEN S.[DayOfWeek] = 6 THEN 'Friday'
       WHEN S.[DayOfWeek] = 7 THEN 'Saturday'
       ELSE 'BAD' 
   END AS [DayOfWeek], 
       isOpen
  FROM MyTable S
 WHERE StoreID = @I_StoreID
 ORDER BY S.[DayOfWeek]  

Right now it returns just a Monday and Tuesday record because that’s all that exists int he table, but I want it to also return the other rows even though there are no records currently for them. Thanks!

Edit:

Here is what I have …

  StoreID | DayOfWeek | isOpen

      22     Sunday      0
      22     Monday      1
      29     Sunday      0

Here is what I’m hoping to get…

  StoreID | DayOfWeek | isOpen

      22     Sunday      0
      22     Monday      1
      22     Tuesday     NULL
       ....
      22     Saturday    NULL

      29     Sunday      1
      29     Monday      NULL 
      29     Tuesday     NULL
       ....
      29     Saturday    NULL

Answer 1

You can use this solution:

SELECT
    a.StoreID,
    a.weekdayname,
    b.isOpen
FROM
(
    SELECT *
    FROM
    (
        SELECT DISTINCT StoreID
        FROM MyTable
    ) aa
    CROSS JOIN
    (
        SELECT 1 AS weekdaynum, 'Sunday' AS weekdayname UNION ALL
        SELECT 2, 'Monday'                UNION ALL
        SELECT 3, 'Tuesday'               UNION ALL
        SELECT 4, 'Wednesday'             UNION ALL
        SELECT 5, 'Thursday'              UNION ALL
        SELECT 6, 'Friday'                UNION ALL
        SELECT 7, 'Saturday'
    ) bb
) a
LEFT JOIN
    MyTable b ON a.StoreID = b.StoreID AND 
                 a.weekdaynum = b.[DayOfWeek]
WHERE
    a.StoreID = @I_StoreID
ORDER BY
    a.StoreID, a.weekdaynum

Here, we manually select all weekday names and CROSS JOIN them with each distinct StoreID. We then wrap the result of that selection in the FROM clause and perform a LEFT JOIN back onto the main table on the condition that StoreID as well as the weekday number match. If not, then the isOpen field will be NULL, but the StoreID and corresponding weekday will still display.

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SQLFiddle Demo