Question

I’ve got a software suite that is based off of multiple libraries where:

1 library = 1 SQL Database.

Different users can have different access to different libraries.

In addition, the databases are named in a specific manner to help identify which are “mine” and which aren’t.

I’d like to create a stored procedure that takes a variable called @UserName and returns the databases that have a name starting with MYDB, where @UserName is found in a table USERS.

I’m figuring that I’ll start with EXEC sp_databases, but I’m unsure how to continue.

What I need to know is:

1. How do I iterate the results of sp_databases to pull out just the databases that have a name matching my pattern?
2. How do I then check for @UserName in the [USER NAME] column of the USERS table of each database returned from #1?

I’m guessing it has something to do with temp tables and cursors, but I’m not really sure where to start.

Any help?

Thanks!

Answer 1

Here is some proof of concept code to show you an approach. sys.databases contains a more accessible list of databases. You’ll pretty much have to use dynamic sql at some point though.

CREATE PROCEDURE MyDBs @userName VARCHAR(255)
AS
BEGIN

DECLARE @max INT
DECLARE @i INT 
DECLARE @sql VARCHAR(500)

CREATE TABLE #SQL
(
    rid int identity primary key clustered,
    query varchar(500)
)

INSERT INTO #SQL(query)
SELECT 'SELECT * FROM ['+ name '+].USERS WHERE username = @UserName'
FROM master.sys.databases
WHERE NAME LIKE '%yourpattern%'

SELECT @max = @@rowcount, @i = 1

WHILE @i <= @max
BEGIN
     SELECT @sql = query FROM #sql WHERE rid = @i
     EXEC @sql
     SET @i = @i + 1
END 

DROP TABLE #SQL