What will the last two lines print? DECLARE @test VARCHAR(2) DECLARE @first VARCHAR(4) DECLARE @second VARCHAR(4) SELECT @first = ISNULL(@test, 'test') SELECT @second = COALESCE(@test, 'test') PRINT @first PRINT @second

253.

What will the last two lines print? 

DECLARE @test VARCHAR(2) 
DECLARE @first VARCHAR(4) 
DECLARE @second VARCHAR(4) 

SELECT @first = ISNULL(@test, 'test') SELECT @second = COALESCE(@test, 'test') 
PRINT @first PRINT @second

te te

te test

test test

Error

View Description

ISNULL() accepts two parameters. The first is evaluated, and if the value is null, the second value is returned (regardless of whether or not it is null). The following queries will return the second parameter in both cases:

SELECT ISNULL(NULL, 1)
--Returns 1
SELECT ISNULL(NULL, NULL)
--Returns NULL

Coalesce returns the first non-null expression in a list of expressions. The list can contain two or more items, and each item can be of a different data type. The following are valid examples of COALESCE:

SELECT COALESCE(NULL, 1)
--Returns 1

SELECT COALESCE(NULL, 3, NULL, 1)
--Returns 3