CS 3430 Lecture Notes - Lecture 17: Alphabetical Order, Pattern Matching, Minit Records

• School: App State
• Department: Computer Science
• Course: CS 3430
• Professor: Mohammad Mohebbi

Document Summary

The basic statement for retrieving information from a database. Sql allows a table to have two or more tuples that are identical in all their attribute values, if the table does not have a key attribute or the retrieving query does not include the primary key. is a list of attribute names whose values are to be retrieved by the query. is a list of the relation names required to process the query. is a conditional expression that identifies the tuples to be retrieved by the query. Conditional expression use logical comparison operators =, , >=, and <>. First query example: retrieve the birth date and address of the employee(s) whose name is (cid:858)joh(cid:374) b. Where f(cid:374)a(cid:373)e = (cid:858)joh(cid:374)(cid:859) and mi(cid:374)it = (cid:858)b(cid:859) and lname = (cid:858)s(cid:373)ith(cid:859); Retrieve the name and address of all employees who work for the (cid:858) esear(cid:272)h(cid:859) depart(cid:373)e(cid:374)t. Where d(cid:374)a(cid:373)e = (cid:858) esear(cid:272)h(cid:859) and dnumber = dno;