How to pass an array into a SQL Server stored procedure

Question

How to pass an array into a SQL Server stored procedure?

For example, I have a list of employees. I want to use this list as a table and join it with another table.

Answer 1

As others have noted above, one way to do this is to convert your array to a string and then split the string inside SQL Server.

As of SQL Server 2016, there's a built-in way to split strings called

STRING_SPLIT()

It returns a set of rows that you can insert into your temp table (or real table).

DECLARE @str varchar(200)
SET @str = "123;456;789;246;22;33;44;55;66"
SELECT value FROM STRING_SPLIT(@str, ';')

would yield:

value
-----
  123
  456
  789
  246
   22
   33
   44
   55
   66

If you want to get fancier:

DECLARE @tt TABLE (
    thenumber int
)
DECLARE @str varchar(200)
SET @str = "123;456;789;246;22;33;44;55;66"

INSERT INTO @tt
SELECT value FROM STRING_SPLIT(@str, ';')

SELECT * FROM @tt
ORDER BY thenumber

would give you the same results as above (except the column name is "thenumber"), but sorted. You can use the table variable like any other table, so you can easily join it with other tables in the DB if you want.

Note that your SQL Server install has to be at compatibility level 130 or higher in order for the STRING_SPLIT() function to be recognized. You can check your compatibility level with the following query:

SELECT compatibility_level
FROM sys.databases WHERE name = 'yourdatabasename';

Most languages (including C#) have a "join" function you can use to create a string from an array.

int[] myarray = {22, 33, 44};
string sqlparam = string.Join(";", myarray);

Then you pass sqlparam as your parameter to the stored procedure above.