How to SET Default value in SQL Server case statement? - sql-server

Question

I have a scenario like to display Status and Count. Look at the below model
Status Counts
--------------- --------
Completed 10
In Progress 6
Others 0
I have this code:
SELECT
CASE
WHEN Status = 'I' THEN 'IN PROGRESS'
WHEN Status = 'O' THEN 'Others'
WHEN Status = 'C' THEN 'COMPLETED'
END AS ' Status',
COUNT(Status) AS ' Counts'
FROM
table1
I have values for only Completed and InProgress. Currently I am getting only two rows. But I need three rows including Others and it's count should be 0 - how to do it in SQL?

Answer 1

Add an "else", like this:
SELECT CASE
WHEN Status= 'I' THEN 'IN PROGRESS'
WHEN Status= 'C' THEN 'COMPLETED'
ELSE 'Others'
END AS ' Status'
FROM table1

Answer 2

From my understanding you have a main table with status values in it, which I'll simplify to this:
CREATE TABLE #MainTable
(
id INT,
[status] NVARCHAR(1)
)
Your problem is that if there are no rows with the status O for Others, you're not getting a 0 when you group the rows to get counts.
I suggest you create a Status table to link to with a RIGHT JOIN. This will also get rid of the need for your CASE statements.
Full solution:
CREATE TABLE #MainTable
(
id INT ,
[status] NVARCHAR(1)
);
INSERT INTO #MainTable
( id, [status] )
VALUES ( 1, 'I' ),
( 2, 'I' ),
( 3, 'I' ),
( 4, 'I' ),
( 5, 'C' ),
( 6, 'C' );
CREATE TABLE #status
(
[status] NVARCHAR(1) ,
[statusText] NVARCHAR(15)
);
INSERT INTO #status
( status, statusText )
VALUES ( 'I', 'In Progress' ),
( 'C', 'Completed' ),
( 'O', 'Others' );
SELECT s.statusText ,
COUNT(t.[status]) StatusCount
FROM #MainTable t
RIGHT JOIN #status s ON s.status = t.status
GROUP BY s.statusText;
DROP TABLE #MainTable;
DROP TABLE #status;
Produces:
statusText StatusCount
Completed 2
In Progress 4
Others 0
In the above example it joins on the I,O,C string values, which I would suggest that you replace with ID values. Then you could do this:
CREATE TABLE #MainTable
(
id INT ,
statusId INT
);
CREATE TABLE #status
(
statusId INT ,
statusShort NVARCHAR(1) ,
statusText NVARCHAR(15)
);
SELECT t.id ,
t.statusId ,
s.statusId ,
s.statusShort ,
s.statusText
FROM #MainTable t
RIGHT JOIN #status s ON s.statusId = t.statusId
DROP TABLE #MainTable;
DROP TABLE #status;