employees
的表,包含以下列:id
, name
, department
, salary
。,,以下是一个查询所有在"Sales"部门工作的员工及其薪水的SQL语句:,,``sql,SELECT name, salary FROM employees WHERE department = 'Sales';,
``GROUP BY
和HAVING
子句。假设你有一个名为users
的表,并且你想查找在email
列中重复的数据,你可以使用以下SQL语句:,,``sql,SELECT email, COUNT(*),FROM users,GROUP BY email,HAVING COUNT(*) > 1;,
`,,这个查询会返回所有在
email`列中出现超过一次的记录及其出现的次数。sql,SELECT column1, COUNT(*) as count,FROM table_name,GROUP BY column1,HAVING count > 1;,
``sql,SELECT column1, column2, COUNT(*),FROM table_name,GROUP BY column1, column2,HAVING COUNT(*) > 1;,
``GROUP BY
和 HAVING
子句实现。GROUP BY
和 HAVING
子句组合来识别重复行。Powered By Z-BlogPHP 1.7.3
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