case statement in sql
Case Statement basically
Like IF - THEN - ELSE statement.
The CASE statement goes through conditions
and returns a value when the
first condition is met and
once a condition is true,
it will stop reading and return the result.
If no conditions are true,
it returns the value in the ELSE clause.
If there is no ELSE part and
no conditions are true, it returns NULL.
FOR EXAMPLE =
CASE
WHEN condition1 THEN result1
WHEN condition2 THEN result2
WHEN conditionN THEN resultN
ELSE result
END
-- example:
SELECT
CASE
WHEN (1+6 = 6) THEN 'A'
WHEN (1+6 = 7) THEN 'B'
WHEN (1+6 = 8) THEN 'C'
ELSE 'D'
END
FROM DUAL;
Result would be 'B' since it is the first
correct answer