SQL Server procedure declare a list - sql

Question

My SQL code is fairly simple. I'm trying to select some data from a database like this:
SELECT * FROM DBTable
WHERE id IN (1,2,5,7,10)
I want to know how to declare the list before the select (in a variable, list, array, or something) and inside the select only use the variable name, something like this:
VAR myList = "(1,2,5,7,10)"
SELECT * FROM DBTable
WHERE id IN myList

Answer 1

You could declare a variable as a temporary table like this:
declare #myList table (Id int)
Which means you can use the insert statement to populate it with values:
insert into #myList values (1), (2), (5), (7), (10)
Then your select statement can use either the in statement:
select * from DBTable
where id in (select Id from #myList)
Or you could join to the temporary table like this:
select *
from DBTable d
join #myList t on t.Id = d.Id
And if you do something like this a lot then you could consider defining a user-defined table type so you could then declare your variable like this:
declare #myList dbo.MyTableType

Answer 2

That is not possible with a normal query since the in clause needs separate values and not a single value containing a comma separated list. One solution would be a dynamic query
declare #myList varchar(100)
set #myList = '1,2,5,7,10'
exec('select * from DBTable where id IN (' + #myList + ')')

Answer 3

You can convert the list of passed values into a table valued parameter and then select against this list
DECLARE #list NVARCHAR(MAX)
SET #list = '1,2,5,7,10';
DECLARE #pos INT
DECLARE #nextpos INT
DECLARE #valuelen INT
DECLARE #tbl TABLE (number int NOT NULL)
SELECT #pos = 0, #nextpos = 1;
WHILE #nextpos > 0
BEGIN
SELECT #nextpos = charindex(',', #list, #pos + 1)
SELECT #valuelen = CASE WHEN #nextpos > 0
THEN #nextpos
ELSE len(#list) + 1
END - #pos - 1
INSERT #tbl (number)
VALUES (convert(int, substring(#list, #pos + 1, #valuelen)))
SELECT #pos = #nextpos;
END
SELECT * FROM DBTable WHERE id IN (SELECT number FROM #tbl);
In this example the string passed in '1,2,5,7,10' is split by the commas and each value is added as a new row within the #tbl table variable. This can then be selected against using standard SQL.
If you intend to reuse this functionality you could go further and convert this into a function.

Answer 4

I've always found it easier to invert the test against the list in situations like this. For instance...
SELECT
field0, field1, field2
FROM
my_table
WHERE
',' + #mysearchlist + ',' LIKE '%,' + CAST(field3 AS VARCHAR) + ',%'
This means that there is no complicated mish-mash required for the values that you are looking for.
As an example, if our list was ('1,2,3'), then we add a comma to the start and end of our list like so: ',' + #mysearchlist + ','.
We also do the same for the field value we're looking for and add wildcards: '%,' + CAST(field3 AS VARCHAR) + ',%' (notice the % and the , characters).
Finally we test the two using the LIKE operator: ',' + #mysearchlist + ',' LIKE '%,' + CAST(field3 AS VARCHAR) + ',%'.

Answer 5

Alternative to #Peter Monks.
If the number in the 'in' statement is small and fixed.
DECLARE #var1 varchar(30), #var2 varchar(30), #var3 varchar(30);
SET #var1 = 'james';
SET #var2 = 'same';
SET #var3 = 'dogcat';
Select * FROM Database Where x in (#var1,#var2,#var3);

Answer 6

If you want input comma separated string as input & apply in in query in that then you can make Function like:
create FUNCTION [dbo].[Split](#String varchar(MAX), #Delimiter char(1))
returns #temptable TABLE (items varchar(MAX))
as
begin
declare #idx int
declare #slice varchar(8000)
select #idx = 1
if len(#String)<1 or #String is null return
while #idx!= 0
begin
set #idx = charindex(#Delimiter,#String)
if #idx!=0
set #slice = left(#String,#idx - 1)
else
set #slice = #String
if(len(#slice)>0)
insert into #temptable(Items) values(#slice)
set #String = right(#String,len(#String) - #idx)
if len(#String) = 0 break
end
return
end;
You can use it like :
Declare #Values VARCHAR(MAX);
set #Values ='1,2,5,7,10';
Select * from DBTable
Where id in (select items from [dbo].[Split] (#Values, ',') )
Alternatively if you don't have comma-separated string as input, You can try Table variable OR TableType Or Temp table like: INSERT using LIST into Stored Procedure