SQLServer重用语句

  1.删除表里90%数据

DELETE T 

FROM (SELECT TOP (90) PERCENT * 
      FROM [KS_DataBase2017].[dbo].[KS_EquipRec20170518] where ColTime >='2017-05-18' and ColTime <'2017-05-18 06:00'

      ORDER BY NEWID()) T

2.查询一年内每个月总记录

SELECT    COUNT(*) 
FROM      table_emp 
WHERE     YEAR(ARR_DATE) = '2012' 
GROUP BY  MONTH(ARR_DATE)