ssql select case code example
Example 1: sql case
-- NOTE: this is for SQL-Oracle specifically
/*
NB: Please like Mingles444 post, I derived this from him/her
*/
-- syntax: (Retrieved from grepper:Mingles444)
CASE
WHEN condition1 THEN result1
WHEN condition2 THEN result2
WHEN conditionN THEN resultN
ELSE result
END
-- example:
SELECT
CASE
WHEN (1+6 = 6) THEN
WHEN (1+6 = 7) THEN
WHEN (1+6 = 8) THEN
ELSE
END
FROM DUAL;
-- OUTPUT: B
Example 2: case when switch in SQL
-- Case Eg.) to retrive the MAX value of a Field
-- if there are entries for the Field in table MAX value will be returned
-- But if there is no entries at all for the Field in tabel MAX will return
-- Null as the output. But Using Case When we can check it out return zero
-- or any other value if there is no enties for the Field in table..
SELECT
CASE -- Like Switch Case
WHEN -- First When condition
(MAX(BILLID) IS NULL) -- Condition
THEN 1 -- output (We can also add more When conditions like Above)
ELSE -- When WHEN Condition not Satisfied Below will be Executed.
(MAX(BILLID)) -- output
END
as MAXBILLID from DUAL;
-- Final Output
-- If there is no entry in the Field for the table
-- BILLID
-- 1
-- If there are entries MAX of that Field value from the table
-- BILLID
-- 10