Constraints in SQL Server are used to enforce rules and relationships on the data stored in tables. They ensure data integrity and maintain consistency within the database. In a previous blog post, we discussed how to enable and disable all constraints in a SQL Server database. However, it was brought to my attention that this method does not work in Azure SQL Database (WASD), as it is a Database as a Service (DBaaS) platform.

While some system commands are not available in SQL Azure, we can still achieve the same effect using Dynamic Management Views (DMVs). In this article, we will explore an alternative approach to enable and disable constraints in SQL Azure.

Disabling Constraints

To disable all constraints for a database in SQL Azure, we can use the following script:

-- Get ALTER TABLE Script for all tables to Disable all constraints for database
SELECT 'ALTER TABLE [' + s.name + '].[' + o.name + '] WITH CHECK CHECK CONSTRAINT [' + i.name + ']'
FROM sys.foreign_keys i
INNER JOIN sys.objects o ON i.parent_object_id = o.OBJECT_ID
INNER JOIN sys.schemas s ON o.schema_id = s.schema_id

This script generates a set of commands that need to be executed explicitly on the SQL Azure server. It disables all constraints for each table in the database.

Enabling Constraints

To enable all constraints for a database in SQL Azure, we can use the following script:

-- Get ALTER TABLE Script for all tables to Enable all constraints for database
SELECT 'ALTER TABLE [' + s.name + '].[' + o.name + '] NOCHECK CONSTRAINT all'
FROM sys.foreign_keys i
INNER JOIN sys.objects o ON i.parent_object_id = o.OBJECT_ID
INNER JOIN sys.schemas s ON o.schema_id = s.schema_id

Similar to the previous script, this script generates a set of commands that need to be executed explicitly on the SQL Azure server. It enables all constraints for each table in the database.

It is important to note that executing these scripts will not make any immediate changes to the database. The output of the scripts is a set of commands that you need to run separately on the SQL Azure server.

If you are working with SQL Azure and require the capability to enable or disable constraints, this alternative approach using DMVs can help you achieve the desired result. I would love to hear about your experiences and any other methods you have used to work with constraints in SQL Azure.