sp_MSforeachtable can be used to loop through all the tables in your databases. Here are some common usages of this useful stored procedure:

1. Display the size of all tables in a database



USE NORTHWIND
EXEC sp_MSforeachtable @command1="EXEC sp_spaceused '?'"



2. Display Number of Rows in all Tables in a database



USE YOURDBNAME
EXEC sp_MSforeachtable 'SELECT ''?'', Count(*) as NumberOfRows FROM ?'



3. Rebuild all indexes of all tables in a database



USE YOURDBNAME
EXEC sp_MSforeachtable @command1="print '?' DBCC DBREINDEX ('?', ' ', 80)"



Note: DBCC DBREINDEX has been deprecated in SQL 2005. Microsoft says "This feature will be removed in a future version of Microsoft SQL Server. Avoid using this feature in new development work, and plan to modify applications that currently use this feature. Use ALTER INDEX instead."

4. Disable all constraints of all tables in a database



USE YOURDBNAME
EXEC sp_MSforeachtable @command1="ALTER TABLE ? NOCHECK CONSTRAINT ALL" 



5. Disable all Triggers of all tables in a database



USE YOURDBNAME
EXEC sp_MSforeachtable 'ALTER TABLE ? DISABLE TRIGGER ALL'



6. Delete all data from all tables in your database



-- disable referential integrity
EXEC sp_MSForEachTable 'ALTER TABLE ? NOCHECK CONSTRAINT ALL'
EXEC sp_MSForEachTable '
    IF OBJECTPROPERTY(object_id(''?''), ''TableHasForeignRef'') = 1
        DELETE FROM ?
    ELSE
        TRUNCATE TABLE ?
'
GO
-- enable referential integrity again
EXEC sp_MSForEachTable 'ALTER TABLE ? CHECK CONSTRAINT ALL'
GO



7. To RESEED all table to 0, use this script



EXEC sp_MSForEachTable ' 
    IF OBJECTPROPERTY(object_id(''?''), ''TableHasIdentity'') = 1 
        DBCC CHECKIDENT (''?'', RESEED, 0) 
' 
GO 


The two tips shown above have been taken from http://blogs.officezealot.com/mauro/archive/2006/03/12/9402.aspx and http://www.sqljunkies.com/WebLog/roman/archive/2006/03/08/18620.aspx


8. Reclaim space from dropped variable-length columns in tables or indexed views



USE YOURDBNAME
EXEC sp_MSforeachtable 'DBCC CLEANTABLE(0,''?'') WITH NO_INFOMSGS; ';



9. Update Statistics of all Tables in a database



USE YOURDBNAME
EXEC sp_MSforeachtable 'UPDATE statistics ? WITH ALL'