You can use the Oracle Schema Manager with the name/password scott/tiger
. The human resources database contains three tables that describe employees, their salary grades, and the departments to which they belong.
The Oracle table structures are shown below:
Table 1. EMP Table EMPNO | ENAME | JOB | MGR | HIREDATE | SAL | COMM | DEPTNO |
7369 | SMITH | CLERK | 7902 | 17-DEC-80 | 800 | | 20 |
7499 | ALLEN | SALESMAN | 7698 | 20-FEB-81 | 1600 | 300 | 30 |
7521 | WARD | SALESMAN | 7698 | 22-FEB-81 | 1250 | 500 | 30 |
7566 | JONES | MANAGER | 7839 | 02-APR-81 | 2975 | | 20 |
7654 | MARTIN | SALESMAN | 7698 | 28-SEP-81 | 1250 | 1400 | 30 |
7698 | BLAKE | MANAGER | 7839 | 01-MAY-81 | 2850 | | 30 |
Table 2. SALGRADE Table GRADE | LOSAL | HISAL |
1 | 700 | 1200 |
2 | 1201 | 1400 |
3 | 1401 | 2000 |
4 | 2001 | 3000 |
5 | 3001 | 9999 |
Table 3. DEPT Table DEPTNO | DNAME | LOC |
10 | ACCOUNTING | NEW YORK |
20 | RESEARCH | DALLAS |
30 | SALES | CHICAGO |
40 | OPERATIONS | BOSTON |
When evaluating the table data, look for associations
between columns or tables. For example, DEPTNO is a column in two tables. Each employee has an EMPNO, and a manager indicated as an EMPNO. In both cases, a relationship exists between the data. If a column in a table is a classification (each row is a “kind of” ), then a type hierarchy should be built. For example, Clerk, Manager, and Salesman are all kinds of employees while much of the other data is descriptive. For example, the location of a department or the employee salary could be considered attributes. Dates are always attributes.