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文件名称：单行子查询-SQL语言基础
文件大小：5.26MB
文件格式：PPT
更新时间：2021-04-25 19:38:21
SQL 基础
单行子查询
*
操作符
=
>
>=
<
<=
<>
含义
等于
大于
大于或者等于
小于
小于或者等于
不等于
仅返回一行
使用单行的比较操作符
*
Single-Row Subqueries
A single-row subquery is one that returns one row from the inner SELECT statement. This type of subquery uses a single-row operator. The slide gives a list of single-row operators.
Example
Display the employees whose job title is the same as that of employee 7369.
ENAME JOB
---------- ---------
JAMES CLERK
SMITH CLERK
ADAMS CLERK
MILLER CLERK
SQL> SELECT ename, job
2 FROM emp
3 WHERE job =
4 (SELECT job
5 FROM emp
6 WHERE empno = 7369);