1. 1Fundamentals of Database Systems 기본키에 밑줄을 그은 COMPANY 관계 데이타베이스 스키마 FNAMEMINITLNAMESSNBDATEADDRESSSEXSALARYSUPERSSNDNO EMPLOYEE DNAMEDNUMBERMGRSSNMGRSTARTDATE DEPARTMENT DNUMBERDLOCATION DEPT_LOCATION PNAMEPNUMBERPLOCATIONDNUM PROJECT ESSNPNOHOURS WORKS_ON ESSNDEPENDENT_NAMESEX DEPENDENT BDATERELATIONSHIP

2. 2Fundamentals of Database Systems COMPANY 스키마의 관계 데이타베이스 상태 EMPLOYEE FNAME John Franklin Alicia Jennifer Ramesh Joyce Ahmad James MINIT B T J S K A V E LNAME Smith Wong Zelaya Wallace Narayn English Jabbar Borg SSN 123456789 333445555 999887777 987654321 666884444 453453453 987987987 888665555 BDATE 09-JAN-55 08-DEC-45 19-JUL-58 20-JUN-31 15-SEP-52 31-JUL-62 29-MAR-59 10-NOV-27 ADDRESS 731 Fondren, Houston, TX 638 Voss, Houston, TX 3321 Castle, Spring, TX 291 Berry, Bellaire, TX 975 Fire Oak, Humble, TX 5631 Rice, Houston, TX 980 Dallas, Houston, TX 450 Stone, Houston, TX SEX M F M F M SALARY 30000 40000 25000 43000 38000 25000 55000 SUPERSSN 333445555 888665555 987654321 888665555 333445555 987654321 null DNO 5 4 5 4 1 DEPARTMENT DNAME Research Administration Headquarters DNUMBER 5 4 1 MGRSSN 333445555 987654321 888665555 MGRSTARTDATE 22-MAY-78 01-JAN-85 19-JUN-71 DEPT_LOCATIONS DNUMBER 1 4 5 DLOCATION Houston Stafford Bellaire Sugarland Houston

3. 3Fundamentals of Database Systems COMPANY 스키마의 관계 데이타베이스 상태 (cont.) WORKS_ON ESSN 123456789 666884444 453453453 333445555 999887777 987987987 987654321 888665555 PNO 1 2 3 1 2 3 10 20 30 10 30 20 HOURS 32.5 7.5 40.0 20.0 10.0 30.0 10.0 35.0 5.0 20.0 15.0 null PROJECT PNAME ProductX ProductY ProductZ Computerization Reorganization Newbenefits PNUMBER 1 2 3 10 20 30 PLOCATION Bellaire Sugarland Houston Stafford Houston Stafford DNUM 5 4 1 4 DEPENDENT ESSN 333445555 987654321 123456789 DEPENDENT_NAME Alice Theodore Joy Abner Michael Allice Elizabeth SEX F M F M F BDATE 05-APR-76 25-OCT-73 03-MAY-48 29-FEB-32 01-JAN-78 32-DEC-78 05-MAY-57 RELATIONSHIP DAUGHTER SON SPOUSE SON DAUGHTER SPOUSE

4. 4Fundamentals of Database Systems COMPANY 데이타베이스 스키마에 표시된 참조 무결성 제약 조건들 FNAMEMINITLNAMESSNBDATEADDRESSSEXSALARYSUPERSSNDNO EMPLOYEE DNAMEDNUMBERMGRSSNMGRSTARTDATE DEPARTMENT DNUMBERDLOCATION DEPT_LOCATION PNAMEPNUMBERPLOCATIONDNUM PROJECT ESSNPNOHOURS WORKS_ON ESSNDEPENDENT_NAMESEX DEPENDENT BDATERELATIONSHIP 외래키는  동일한  릴레이션의  애트리뷰트를  참조할  수도  있음