比较运算符:=等于,>大于,<小于,>=大于等于,<=小于等于,<>不等于(或 !=,^=)
例:查询部门ID等于10的员工信息;
SQL@itkaifang> SELECT empno,ename,sal,deptno FROM emp WHERE deptno=10; EMPNO ENAME SAL DEPTNO ---------- ---------- ---------- ---------- 7782 CLARK 2450 10 7839 KING 5000 10 7934 MILLER 1300 10 SQL@itkaifang>
例:查询工资大于3000的员工信息;
SQL@itkaifang> SELECT empno,ename,sal,deptno FROM emp WHERE sal>3000; EMPNO ENAME SAL DEPTNO ---------- ---------- ---------- ---------- 7839 KING 5000 10 SQL@itkaifang>
例:查询工资小于等于3000的员工信息;
SQL@itkaifang> SELECT empno,ename,sal,deptno FROM emp WHERE sal>=3000; EMPNO ENAME SAL DEPTNO ---------- ---------- ---------- ---------- 7788 SCOTT 3000 20 7839 KING 5000 10 7902 FORD 3000 20 SQL@itkaifang>
例:查询工资不等于3000的员工信息;
SQL@itkaifang> SELECT empno,ename,sal,deptno FROM emp WHERE sal!=3000; EMPNO ENAME SAL DEPTNO ---------- ---------- ---------- ---------- 7369 SMITH 800 20 7499 ALLEN 1600 30 7521 WARD 1250 30 7566 JONES 2975 20 7654 MARTIN 1250 30 7698 BLAKE 2850 30 7782 CLARK 2450 10 7839 KING 5000 10 7844 TURNER 1500 30 7876 ADAMS 1100 20 7900 JAMES 950 30 7934 MILLER 1300 10 12 rows selected. SQL@itkaifang>