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ORDER BY with bool> date> null in SQLite

I have a Loooooooooooong SELECT ending with an ORDER BY which can include the following values:

  • checked (1 or 0)
  • date (YYYY-MM-DD)
  • time (HH: MM: SS)

I want to order the query result like this:

|__checked = 0
|            |__ date ASC
|            |__ time ASC
|            |__ date && time are null  
|__checked = 1
             |__ date ASC
             |__ time ASC
             |__ date && time are null

Currently I have something simple like "ORDER BY i1.checked, date, time", but the problem is that items with empty dates and times stay on top.

Here's the whole query if you ever thought you needed all the data to find a suitable solution. Do not Cry.

SELECT i1._id AS _id, i1.title AS title, i1.checked AS checked, 

   // count the children (-1 is because the closure table include a relation between any item and itself)   
   (count( c1.item_id )  - 1) AS children_count, 

   // count the unchecked children 
   (SELECT (COUNT(DISTINCT i2._id) ) 
   FROM item AS i2 JOIN closure AS c2 ON (i2._id = c2.item_id) 
   WHERE c2.ancestor_id = i1._id 
   AND i2.checked = 0  
   AND c2.item_id NOT IN (0, i1._id)) AS unchecked_children_count, 

   // get the closest deadlines among the children :
   // if there is a date but no time, time is set to 00:00:00
   // if there is a time but not date, date is set to today
   // if there is no date nor time, both are set to an empty string

   // date
   ifnull(nullif((SELECT ifnull(nullif(i3.date, ""), date()) AS subdate
                  FROM item AS i3 JOIN closure AS c3 ON (i3._id = c3.item_id) 
                  WHERE c3.ancestor_id = i1._id
                  AND (i3.date OR i3.time) 
                  ORDER By subdate, ifnull(nullif(i3.time, ""), "00:00:00") 
                  LIMIT 1), ""), "") AS date, 

   // time           
   ifnull(nullif((SELECT ifnull(nullif(i4.time, ""), "00:00:00") AS subtime
                  FROM item AS i4 JOIN closure AS c4 ON (i4._id = c4.item_id) 
                  WHERE c4.ancestor_id = i1._id 
                  AND (i4.date OR i4.time) 
                  ORDER By ifnull(nullif(i4.date, ""), date()), subtime 
                  LIMIT 1), ""), "") AS time 

FROM item AS i1 JOIN closure AS c1 ON ( i1._id = c1.ancestor_id ) 
WHERE i1.parent_id = 0
AND c1.item_id != 0 

GROUP BY c1.ancestor_id 

ORDER BY i1.checked, date, time

Items are organized in a tree with a parent_id and a closure table.

+1


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2 answers 


ORDER BY il.checked, 
         CASE WHEN date IS NULL AND time IS NULL THEN 1 ELSE 0 END, 
         date, time


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You can create an extra column temp

in the wrapped element around your entire sql so you can add artificial ordering.



SELECT
    EACH_COLUMN
    , ...
    , CASE WHEN DATECol IS NULL AND TimeCol is NULL THEN 0 
         WHEN TimeCol is NULL THEN 1
         WHEN DATECol IS NULL THEN 2
         ELSE 3 END As ORDERCOL...

FROM
(
     INNER MESS OF ALL THE STUFF IN YOUR QUERY
)

ORDER BY
    ORDERCol DESC --Preserves order of BothCols Populated, Null Dates Next, Null Times Next, Both Nulls Last
    , Checked
    , Date
    , Time
+2


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