In this post, I am sharing the use of sp_MSforeachtable stored procedure of SQL Server.
This is an undocumented object of SQL Server, but still, you can use this stored procedure.

When we require executing same T-SQL command for all the tables, we can use this stored procedure.
Many times we need to run drop/truncate command for all tables or REINDEX all tables, at that point instead of the manual script we can use this stored procedure.

Sharing few examples:

Truncate all tables of current database:

EXEC sp_MSforeachtable 'TRUNCATE TABLE ?'

Check the count of all tables:

EXEC sp_MSforeachtable 'TRUNCATE TABLE ?'

Drop all tables of current database:

EXEC sp_MSforeachtable 'DROP TABLE ?'

REINDEX all tables of current database:

EXEC sp_MSforeachtable 'DBCC DBREINDEX(''?'')'

In this post, I am sharing the script to enable and disable foreign key and check constraint in SQL Server.

During data migration and testing purpose, Database Developer requires to disable Foreign key constraint or Check constraint.

Once you disable constraint, then later you might need enabling again, but during this exercise make sure that all your data changes are correct, and as per the constraint rule otherwise, you should not enable those constraints.

You can disable/enable action only on Foreign Key and Check Constraint.
You cannot perform disable/enable on Primary Key and Unique Key.

Disable All Foreign keys and Check Constraints:

EXEC sp_msforeachtable "ALTER TABLE ? NOCHECK CONSTRAINT ALL"

Enable All Foreign keys and Check Constraints:

EXEC sp_msforeachtable @command1="print '?'", 
@command2="ALTER TABLE ? WITH CHECK CHECK CONSTRAINT ALL"

Disable all the table constraints:

ALTER TABLE table_name NOCHECK CONSTRAINT ALL

Enable all the table constraints:

ALTER TABLE table_name CHECK CONSTRAINT ALL

Disable a single constraint:

ALTER TABLE table_name NOCHECK CONSTRAINT constraint_name

Enable a single constraint:

ALTER TABLE table_name CHECK CONSTRAINT constraint_name