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文件名称：使用比较操作符-SQL语言基础
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更新时间：2021-04-25 19:38:10
SQL 基础
使用比较操作符
*
SQL> SELECT ename, sal, comm
2 FROM emp
3 WHERE sal<=comm;
ENAME SAL COMM
---------- --------- ---------
MARTIN 1250 1400
*
SELECT ename, sal, comm
FROM emp
WHERE sal<=comm;
Using the Comparison Operators
In the example, the SELECT statement retrieves name, salary, and commission from the EMP table, where the employee salary is less than or equal to the commission amount. Note that there is no explicit value supplied to the WHERE clause. The two values being compared are taken from the SAL and COMM columns in the EMP table.
Instructor Note
Rows that have a null value in the COMM column result in a null value for the comparison expression and are effectively not part of the result.