Introduction to Database Systems

CHAPTER 5

STRUCTURED QUERY LANGUAGE

After reading this chapter, the reader will understand:

• The basic features of SQL
• The concept of schema and catalog in SQL
• Different types of data types available in SQL
• DDL commands to create relations in SQL
• Various constraints that can be applied on the attributes of a relation
• DDL commands to alter the structure of a relation
• DML commands to manipulate the data stored in the database
• Various clauses of SELECT command that can be used to extract data from database
• Various set operations like union, intersect, and minus
• The use of INSERT, UPDATE, and DELETE commands to insert, update, and delete tuples in a relation
• Searching of null values in a relation
• The use of various aggregate function in select query ...