ποΈ case
CASE is a conditional expression. It returns the result in the THEN clause if a condition in the WHEN clause evaluates to true. If none of the conditions evaluate to true, it returns the result in the optional ELSE clause. If ELSE is not present, NULL is returned.
ποΈ coalesce
Returns the first non-NULL expression among the input parameters. Returns NULL if non-NULL expressions cannot be found.
ποΈ if
If expr1 evaluates to TRUE, returns expr2. Otherwise, returns expr3.
ποΈ ifnull
If expr1 is NULL, returns expr2. If expr1 is not NULL, returns expr1.
ποΈ nullif
Returns NULL if expr1 is equal to expr2. Otherwise, returns expr1.