What are the basic rules to be followed when you are using SQL SET Operators? Posted in SQL Interview Questions by Chandrasekhar Raparthi On July 10, 2014. No comments Rules: Number of columns in all the result sets should be matched(same). Respective data types should be matched between all the result sets. Share this:GooglePinterestEmailTwitterLinkedInFacebook Tags:set operators,SQL Related Posts Explain any 3 of CODD’s Rules Edgar F. Codd, proposed thirteen rules (0 to 12) How many Clustered Indexes we can create on a table? Why? It is always only one. Clustered indexes sort and Is it possible to create a Foreign key without Primary key? Yes. We can create a Foreign key without having Leave a Reply Cancel reply Your email address will not be published. Required fields are marked *Comment Name * Email * Website Notify me of follow-up comments by email. Notify me of new posts by email.