Week 4 textbook assignment - Chapter 3 review questions 3...

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3. Entity integrity is when each primary key value is unique so that each row in the DB table is uniquely identified. Referential integrity is when the value of a foreign key refers to an already existing and valid row in another relation. These rules are often automatically enforced, however, the design of the DB should conform to these rules because not all RDBMS automatically enforce them. They are important to good database design and also so that the users of the DB can reliably trust the integrity of the information in the DB. 11. Database name: Ch03_NoComp Table name: Employee Attribute Values (column values): EMP_NUM, EMP_LNAME, EMP_INITIAL, EMP_FNAME, DEPT_CODE, JOB_CODE. Data: The text and numbers in every row below the first row. Primary key: EMP_NUM Candidate key: EMP_NUM, EMP_LNAME Probable foreign keys: DEPT_CODE, JOB_CODE, EMP_LNAME Chapter 3 problems 17-22 17. TABLE
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This note was uploaded on 08/02/2009 for the course IST 210 taught by Professor Mcconn,charlotteryoo,jungwoo during the Summer '08 term at Pennsylvania State University, University Park.

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Week 4 textbook assignment - Chapter 3 review questions 3...

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