IN
条件(IN Conditions)是成员资格条件。它测试值或子查询列表中成员的值。
语法
expr [ NOT ] IN ({ expression_list | subquery })
|
( expr [, expr ]... ) [ NOT ] IN ( { expression_list [, expression_list ]... | subquery } )
IN
条件可以测试表达式是表达式列表或子查询的成员,或者多个表达式是表达式列表或子查询的成员。并且每个表达式列表中的表达式必须在数量和数据类型上与运算符 IN
左边的表达式匹配。
示例
IN 示例:相当于 =ANY
,表示集合中所有的成员。
SELECT * FROM employees WHERE job_id IN ('PU_CLERK','SH_CLERK') ORDER BY employee_id;
SELECT * FROM employees WHERE salary IN (SELECT salary FROM employees
WHERE department_id =30) ORDER BY employee_id;
NOT IN 示例:相当于 != ALL
。如果集合中的任何成员为 NULL
,则计算为 false
。
SELECT * FROM employees WHERE salary NOT IN (SELECT salary FROM employees
WHERE department_id = 30) ORDER BY employee_id;
SELECT * FROM employees WHERE job_id NOT IN ('PU_CLERK', 'SH_CLERK')
ORDER BY employee_id;
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