What are the integrity constraints? Explain. 

• Integrity constraints are a set of rules. It is used to maintain the quality of information.
• Integrity constraints ensure that the data insertion, updating, and other processes must be performed in such a way that data integrity is not affected.
• Thus, integrity constraint is used to guard against accidental damage to the database.

1. What integrity constraints may be violated by
2. Inserting a tuple into relation
3. Deleting a tuple from a given relation
4. Updating a tuple in a given relation
5. Bottom-up database design approach is to group the attributes into relations.  This leads to informal design as apposed mapping ERD to Relational schema.  What are the informal design criteria?
6. What are the join conditions for natural join of two relations?
7. What is the difference between 3GL and 4 GL?
8. SQL belongs to what generation of programming Language?
9. What are the advantages and limitations of SQL?
10. Why do you need 3GL (such as PL, C++, Python) and 4GL (SQL) combination for database applications?