selectmax(Salary)from Employee;#2、求小于最大的值 selectmax(Salary)asSecondHighestSalary from Employee where Salary<(selectmax(Salary)from Employee); 第二个思路,先将所有值倒序排,然后输出第二个就行 代码语言:javascript 代码运行次数:0 运行 AI代码解释 select SalaryasSecondHighestSalary from Employee ...
SELECT( (SELECTDISTINCTSalary # distinct不能漏掉,排除重复值FROMEmployeeORDERBYSalaryDESCLIMIT1OFFSET1) )ASSecondHighestSalary limit/offset语法: 1. offset X是跳过X个数据,limit Y是选取Y个数据 2. limit X,Y中表示跳过X个数据,读取Y个数据 有些同学可能会疑惑,为什么要写两个select,不直接使用一个select...
-- 4.LAST_VALUE()示例-- 比较当前销售额与区域最低销售额SELECTsalesperson,region,amount,LAST_VALUE...
select max(Salary) from Employee; # 2、求小于最大的值 select max(Salary) as SecondHighestSalary from Employee where Salary < (select max(Salary) from Employee); 1. 2. 3. 4. 5. 6. 7. 第二个思路,先将所有值倒序排,然后输出第二个就行 AI检测代码解析 select Salary as SecondHighestSalary...
select * from 表名 group by 列名1,列名2这样可以根据多个字段进行分组,这些列名存在顺序关系,假如一整张表按照列名1分为A\B两组,然后再对A\B两组分别按照列名2进行细分,得到A-1、A-2、A-3等组,以及B-1、B-2等组。实例:假设现在整表查询如图使用group by university,gender...
SELECT query = a.text, start_time, percent_complete, eta = dateadd(second,estimated_completion_time/1000, getdate()) FROM sys.dm_exec_requests r CROSS APPLY sys.dm_exec_sql_text(r.sql_handle) a WHERE r.command LIKE 'BACKUP%'; Related content Backup Devices Media Sets, Media Families...
因为窗口函数是 对where或者group by子句 处理后的结果进行操作,所以窗口函数原则上只能写在select子句中。 1.知识点总结: sum(...A...) over(partition by ...B... order by ...C... rows between ...D1 and ...D2...) avg(...A ... ) over(partition by ...B... order by ...C....
(xst.event_session_address = xs.address) WHERE xs.name = 'spinlock_backoff_with_dump'; --get the highest slot count from the bucketizer SELECT @slot_count = @xml_result.value(N'(//Slot/@count)[1]', 'int'); --if the slot count is higher than the threshold in the one minute ...
|+---+---+输出：+---+| SecondHighestSalary |+---+| null |+---+5.2求解ifnull(a,b)函数解释：如果value不是空，结果返回a如果value是空，结果返回bLIMIT子句语法:SELECT column1,column2,...FROM tableLIMIT offset , count;LIMIT子句参数：offset参数指定要返回的第一行的偏移量。第一...
select * from employees where hire_date = (select max(hire_date) from employees); 1. 2. 3. 4. 5. 6. 7. 推荐优先使用子查询,因为如果最大的同时有N个,子查询可以全部查询到,但排序只能排一个 口试: 如果我只需要知道该字段的最值的具体value,那我直接select max from table即可,当然order by ...