pyflink.table.expression.Expression.if_null

Expression.if_null(null_replacement) → pyflink.table.expression.Expression

Returns null_replacement if the given expression is null; otherwise the expression is returned.

This function returns a data type that is very specific in terms of nullability. The returned type is the common type of both arguments but only nullable if the null_replacement is nullable.

The function allows to pass nullable columns into a function or table that is declared with a NOT NULL constraint.

e.g. col(“nullable_column”).if_null(5) returns never null.

New in version 1.12.0.