Conditional Functions
| Function | Description | Example | Result |
|---|---|---|---|
| IF(expr1, expr2, expr3) | Return expr2 if expr1 is TRUE. Otherwise return expr3. expr2 and expr3 must have the lowest common type. | IF(1 > 2, 3, 4) | 4 |
| IFNULL(expr1, expr2) | Return expr1 if it is not NULL. Otherwise return expr2. They must have the same data type. | IFNULL(0, NULL) | 0 |
| value [ NOT ] IN (value1, value2, ...) | Check whether value is (or is not) one of the members of an explicit list. | 1 not in (2, 3) | 1(TRUE) |
| expr1 IS [ NOT ] DISTINCT FROM expr2 | Compares whether two expressions are equal (or not equal) with awareness of nullability, meaning it treats NULLs as known values for comparing equality. | NULL is distinct from NULL | 0(FALSE) |
| IS_NOT_NULL(expr) | Check whether the value is not NULL. | IS_NOT_NULL(1) | 1(TRUE) |
| IS_NULL(expr) | Check whether the value is NULL. | IS_NULL(1) | 0(FALSE) |
| MULTI_IF(cond1, expr1, [cond2, expr2, ...], expr_else) | If cond1 is TRUE, it returns expr1. Otherwise if cond2 is TRUE, it returns expr2, and so on. | MULTI_IF(1 > 2, 3, 4 < 5, 6, 7) | 6 |
| NULLIF(expr1, expr2) | Return NULL if two expressions are equal. Otherwise return expr1. They must have the same data type. | NULLIF(0, NULL) | 0 |