Chapter 4 - Intermediate SQL. In this chapter, we continue our study of SQL. We consider more complex forms of SQL queries, view definition, transactions, integrity constraints, more details regarding SQL data definition, and authorization. | Chapter 4: Intermediate SQL Database System Concepts, 6th Ed. ©Silberschatz, Korth and Sudarshan See for conditions on re-use Chapter 4: Intermediate SQL Join Expressions Views Transactions Integrity Constraints SQL Data Types and Schemas Authorization Database System Concepts - 6th Edition ©Silberschatz, Korth and Sudarshan Joined Relations Join operations take two relations and return as a result another relation. A join operation is a Cartesian product which requires that tuples in the two relations match (under some condition). It also specifies the attributes that are present in the result of the join The join operations are typically used as subquery expressions in the from clause Database System Concepts - 6th Edition ©Silberschatz, Korth and Sudarshan Join operations – Example Relation course Relation prereq Observe that prereq information is missing for CS-315 and course information is missing for CS-437 Database System Concepts - 6th Edition ©Silberschatz, Korth and Sudarshan Outer Join An extension of the join operation that avoids loss of information. Computes the join and then adds tuples form one relation that does not match tuples in the other relation to the result of the join. Uses null values. Database System Concepts - 6th Edition ©Silberschatz, Korth and .
