How to drop multiple databases in SQL Server

Question

Just to clarify, ths isn't really a question, more some help for people like me who were looking for an answer.
A lot of applications create temp tables and the like, but I was surprised when Team Foundation Server created 80+ databases on my test SQL Server. TFS didn't install correctly, and kindly left me to clear up after it. Since each database had a naming convention, rather than delete each database by hand, I remembered how to use cursors and have written what I view to be the most unwise piece of T-SQL ever:

   CREATE TABLE #databaseNames (name varchar(100) NOT NULL, db_size varchar(50), owner varchar(50), dbid int, created date, status text, compatibility_level int);
INSERT #databaseNames
    exec sp_helpdb;

DECLARE dropCur CURSOR FOR
    SELECT name FROM #databaseNames WHERE name like '_database_name_%';
OPEN dropCur;
DECLARE @dbName nvarchar(100);
FETCH NEXT FROM dropCur INTO @dbName;
DECLARE @statement nvarchar(200);
WHILE @@FETCH_STATUS = 0
BEGIN
    SET @statement = 'DROP DATABASE ' + @dbName;
    EXEC sp_executesql @statement;
    FETCH NEXT FROM dropCur INTO @dbName;
END
CLOSE dropCur;
DEALLOCATE dropCur;
DROP TABLE #databaseNames;

It goes without saying that using cursors like this is probably really dangerous, and should be used with extreme caution. This worked for me, and I haven't seen any further damage to my database yet, but I disclaim: use this code at your own risk, and back up your vital data first!
Also, if this should be deleted because it's not a question, I understand. Just wanted to post this somewhere people would look.

Answer 1

this is easy...

use master
go
declare @dbnames nvarchar(max)
declare @statement nvarchar(max)
set @dbnames = ''
set @statement = ''
select @dbnames = @dbnames + ',[' + name + ']' from sys.databases where name like 'name.of.db%'
if len(@dbnames) = 0
    begin
    print 'no databases to drop'
    end
else
    begin
    set @statement = 'drop database ' + substring(@dbnames, 2, len(@dbnames))
    print @statement
    exec sp_executesql @statement
    end

Answer 2

Why not just do this instead?

USE master;
Go
SELECT 'DROP DATABASE ['+ name + ']' 
FROM sys.databases WHERE name like '_database_name_%';
GO

Capture the output of that resultset and then paste it into another query window. Then run that. Why write all this TSQL cursor code?

"When you have a hammer, everything looks like a nail!"..

Answer 3

There is no need to use a cursor, and no need to copy and paste SQL statements. Just run these two lines:

DECLARE @Sql as NVARCHAR(MAX) = (SELECT 'DROP DATABASE ['+ name + ']; ' FROM sys.databases WHERE name LIKE 'DBName%' FOR XML PATH(''))

EXEC sys.sp_executesql @Sql

Of course, any DB matching the criteria will be dropped immediately, so be sure that you know what you are doing.