Is it possible to define full SELECT clause in USE GO clause? - sql-server

Question

I'm trying to define full SELECT clause in USE for a list of databases.
I'm trying to query across all databases in a server to list all available functions. There are about 80 databases so I'm going to use variable table to pass the list of databases to USE clause to be able to switch between every database and run simple query to list functions in there, all through a WHILE loop.
Is it possible to do something like,
USE
(SELECT dBname
From dBList
where rowID=#currentRow)
GO
IF not, any suggestion to do it less painfully than querying databases one by one?
This is what I have done in MS SQL Server 2014 but no joy,
declare #dBaseList Table
( RowID int not null primary key identity(1,1), dBname varchar(100)
)
declare #SeldBname varchar(100)
declare #rowsdBaseList int
declare #currentRow int
insert into #dBaseList (dBname)
SELECT name FROM sys.databases
set #rowsdBaseList=##ROWCOUNT
set #currentRow=0
while #currentRow<#rowsdBaseList
begin
set #currentRow+=1
use
(select #SeldBname=dBname
from #dBaseList
where RowID=#currentRow)
Go
select * from sys.objects where type='FN'
end
It should look something like,
USE
dBname1
GO
select * from sys.objects where type='FN'
USE
dBname2
GO
select * from sys.objects where type='FN'
USE
dBname3
GO
select * from sys.objects where type='FN'
.
.
.
.
.

Answer 1

You should just be able to use a 3 part name in your query:
select * from dBname1.sys.objects where type='FN'
select * from dBname2.sys.objects where type='FN'
select * from dBname3.sys.objects where type='FN'
If you'd prefer to do it programmatically, you can use the (unsupported and undocumented) sp_MSforeachdb proc:
EXEC sp_MSforeachdb 'IF DB_ID(''?'') > 4 BEGIN select * from ?.sys.objects where type=''FN'' END'
The IF DB_ID(''?'') > 4 conditional excludes system databases, which you presumably don't want.
With regard to using a SELECT statement in a USE statement, you can't do it as you have specified in your question. However, you can incorporate it into the sp_MSforeachdb call, should you need to:
EXEC sp_MSforeachdb 'IF DB_ID(''?'') > 4 BEGIN USE ?; select DB_NAME() AS [DatabaseName], * from sys.objects where type=''FN'' END'

Answer 2

Have you tried Dynamic-SQL? Something like the code below, this is just a sample as I don't have right now my machine to actually test it.
SELECT name AS DatabaseName INTO #TEMP FROM master.dbo.sysdatabases
DECLARE #Count INT, #Database VARCHAR(MAX), #Query
SET #Count = (SELECT COUNT(*) FROM #TEMP)
WHILE (#Count) > 0
BEGIN
SET #Database = (SELECT TOP(1) DatabaseName FROM #TEMP)
SET #Query = 'SELECT * FROM ' + #Database + '.sys.objects WHERE type = ''FN'''
EXEC (#sqlCommand)
DELETE FROM #TEMP WHERE DatabaseName = #Database
SET #Count = (SELECT COUNT(*) FROM #TEMP)
END

Answer 3

Below is a method to return the query results from all databases as a single result set and include the database name.
DECLARE #SQL nvarchar(MAX) =
STUFF((
SELECT ' UNION ALL SELECT N''' + name + N''' AS DatabaseName, * FROM ' + QUOTENAME(name) + N'.sys.objects where type=''FN'''
FROM sys.databases
FOR XML PATH(''), TYPE).value('.','nvarchar(MAX)'), 1, 11,'') + N';';
EXEC(#SQL);

Answer 4

use sp_MSforeachdb
use [yourdatabase_in_which_you_store_the_results]
go
--create table functions_in_alldb(db nvarchar(100),fn_name nvarchar(200))
declare #functions_in_alldb as table(db nvarchar(100),fn_name nvarchar(200))
go
--truncate table functions_in_alldb
go
DECLARE #command varchar(1000)
SELECT #command = 'USE ?
if ''?'' not in (''master'',''msdb'',''tempdb'',''model'',''msdb'')
insert into #functions_in_alldb(db,fn_name) SELECT ''?'',name FROM sysobjects WHERE xtype = ''FN'' ORDER BY name'
EXEC sp_MSforeachdb #command
select * from #functions_in_alldb