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
