Overview of Control Flow Functions
| Name | Description |
|---|---|
| CASE | CASE WHEN statement is used to calculate a list of conditions and return one of multiple possible result expressions |
| IF() | IF(expr1,expr2,expr3), when expr1 is TRUE, it returns expr2; otherwise, it returns expr3 |
| IFNULL() | IFNULL(expr1,expr2), when expr1 is not NULL, it returns expr1; otherwise it returns expr2 |
| NULLIF() | NULLIF(expr1,expr2), when expr1 = expr2, returns NULL; otherwise, returns the value of expr1 |