Coalesce

coalesce returns the value of the first argument that is not null. When a non-null value is found, the remaining arguments in the list are not evaluated. If all arguments are null, the result is null. 0-length strings are valid values and are not considered equivalent to null.

Syntax

coalesce(expression1, expression2 [, expression3, ...])

Arguments

coalesce takes two or more expressions as arguments. All of the expressions must have the same data type or be able to be implicitly cast to the same data type.

expression

The expression can be numeric, datetime, or string. It can be a field name, a literal value, or another function.

Return type

coalesce returns a value of the same data type as the input arguments.

Example

The following example retrieves a customer's billing address if it exists, her street address if there is no billing address, or returns “No address listed” if neither address is available.

coalesce(billingAddress, streetAddress, 'No address listed')