string_null

Description

Returns a null value of type string.

This is valuable because some functions, like case(), return more convenient outputs if all their arguments are of the same type.

Return type

string

Domain

This is a scalar function (calculates a single output value for a single input row.)

Categories

• String

Usage

string_null()

Examples

make_col positive_or_null:case(x > 0, x, true, string_null())

Create a column ‘positive_or_null’ which is either a positive string, or the null string.