coalesce

The coalesce function evaluates a list of expressions and returns the first non-null expression.

Syntax

​

    coalesce( Expression_1, Expression_2, ... )

Arguments

​

Expression_i: A scalar expression, to be evaluated.

• All arguments must be of the same type.
• Maximum of 64 arguments is supported.

Results

​

The value of the first Expression_1 whose value isn’t null (or not-empty for string expressions).

Example

​

• coalesce(tolong("not a number"), tolong("42"), 33) returns as 42