Select column, if blank select from another

Question

How does one detect whether a field is blank (not null) and then select another field if it is?

What I really need is a IsBlank function that works the same as IsNul

Answer 1

You could always write an isBlank() function, something like

SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO

CREATE FUNCTION isBlank
(
    @CheckExpression varchar, @ReplacementExpression varchar
)
RETURNS varchar
AS
BEGIN
    IF @CheckExpression IS NOT NULL
    BEGIN
        IF @CheckExpression='' or LEN(@CheckExpression) = 0
        RETURN @ReplacementExpression
    ELSE
        RETURN @CheckExpression
    END

    RETURN @ReplacementExpression
END
GO