Functions with null operation data (oracle version)

Functions with null operation data (oracle version)

The comprehensive data type function NVL (expr1, expr2) returns expr1 if expr1 is not null. If expr1 is null, expr2 is returned. The data types of the two expressions must be the same. NVL2 (expr1, expr2, expr3) returns expr2 if expr1 is not null. If expr1 is null, expr3NULLIF (expr1, expr2) is returned if expr1 and expr2 are the same, otherwise, expr1COALESCE (expr1, expr2 ,..., Exprn) returns the first non-null value in the brackets. Select COALESCE (comm, sal, 100) "bonus" from emp; if there is a bonus, return the bonus. If there is no bonus, return the salary as the bonus, if the bonus and salary are empty, 100 is returned. The alias is "bonus ".