I'm trying to return different data depending on a variable in a SELECT. Something like this:
SELECT
IF @variable = 'YES'
column1, column2
ELSE
column3
FROM TABLE
What is this the proper way to use the IF condition in SQL? Or is there a better alternative to what I'm trying to accomplish?
If you want to return a different number of columns, you'll need to use an IF:
IF @variable = 'YES'
BEGIN
SELECT column1, column2
FROM YourTable
END
ELSE
BEGIN
SELECT column3
FROM YourTable
END
If you want different data on the same column (assuming the same datatype), you could use a CASE:
SELECT CASE WHEN @variable = 'YES' THEN column1 ELSE Column2 AS Data
FROM YourTable
You can use an IF statement, but you'll need to set up multiple queries. You can use a CASE for selecting one column or another, but not to select one or multiple like in your question.
DECLARE @var INT = 1;
DECLARE @test TABLE (
Col1 int,
Col2 int,
Col3 int
)
INSERT INTO @test VALUES (1,2,3)
IF @var = 1
BEGIN
SELECT Col1, Col2
FROM @test
END
ELSE
BEGIN
SELECT Col3
FROM @test
END
