How do I use a comma separated list of values as a filter in T-SQL?

Question

I have a basic SQL query, starting with:

SELECT top 20 application_id, [name], location_id FROM apps

Now, I would like to finish it so that it

Answer 1

You are asking different questions here. This is the answer to your original question (about the ternary operator, but as you can see, you don't need anything like a ternary operator for this):

SELECT top 20 application_id, [name], location_id 
FROM apps
WHERE @lid = 0 OR location_id IN (@lid)

But that was before we knew that @lid was a varchar and could contain different comma separated values.

Well, this (about the csv) is another question which has been asked here before:

Passing an "in" list via stored procedure
T-SQL stored procedure that accepts multiple Id values

Answer 2

See this entry in my blog:

• IN with a comma separated list: SQL Server

If your @lid is a comma-delimited list of integers, use this:

WITH    cd AS
        (
        SELECT  1 AS first, CHARINDEX(',', @lid, 1) AS next
        UNION ALL
        SELECT  next + 1, CHARINDEX(',', @lid, next + 1)
        FROM    cd
        WHERE   next > 0
        ),
        lid AS
        (
        SELECT  CAST(SUBSTRING(@lid, first, CASE next WHEN 0 THEN LEN(@lid) + 1 ELSE next END - first)AS INT) AS id
        FROM    cd
        )
SELECT  d.*
FROM    (
        SELECT  DISTINCT id
        FROM    lid
        ) l
JOIN    apps a
ON      a.location_id = l.id
        AND @lid <> '0'
UNION ALL
SELECT  *
FROM    apps a
WHERE   @lid = '0'

This is much more efficient than using OR constructs.

Answer 3

Try using Case, which serves the purpose of an IIF or a ternary operator. Please check this link http://msdn.microsoft.com/en-us/library/ms181765.aspx

cheers

Answer 4

While it is not exactly a best practice to use 1=1, it does the trick here.

SELECT top 20 application_id, [name], location_id FROM apps
WHERE
  (@lid > 0 and @lid = location_id)
or
  (isnull(@lid, 0) <= 0 and 1=1)

Answer 5

One way is to split the string on the commas, strip out the spaces and insert the values into a temporary table. Then you can join your query against the temp table.

This is a T-SQL code snippet that splits a comma-separated list and inserts the members into a temporary table. Once you've populated the table you can join against it.

-- This bit splits up a comma separated list of key columns
-- and inserts them in order into a table. 
--
if object_id ('tempdb..#KeyCols') is not null
    drop table #KeyCols

create table #KeyCols (
      ,KeyCol           nvarchar (100)
)

set @comma_pos = 0
set @len = len(@KeyCols)
while @len > 0 begin
    set @comma_pos = charindex(',', @KeyCols)
    if @comma_pos = 0 begin
        set @KeyCol = @KeyCols
        set @KeyCols = ''
    end else begin
        set @KeyCol = left (@KeyCols, @comma_pos - 1)
        set @KeyCols = substring(@KeyCols, 
                                 @comma_pos + 1, 
                                 len (@KeyCols) - @comma_pos)
    end
    insert #KeyCols (KeyCol)
    values (@KeyCol)
    set @len = len (@KeyCols)
end

Answer 6

Assuming @locid & @lid are the same, I'm going to use @locid... The following would work. I've split it up to keep it looking good on SO.

SELECT application_id, [name], location_id 
FROM apps
WHERE
  ( 
    @locid = 0
    OR 
    CHARINDEX
    ( 
      ',' + CAST(location_id AS VARCHAR(50)) + ','
      , 
      ',' + @locid + ','
      , 
      0 
    ) > 0
  )