SQL

alter table LianTong_ContractApproveHistoryModels add CreateUserName nvarchar(max) NULL;

EXEC sys.sp_addextendedproperty @name=N'MS_Description', @value=N'创建人名称' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'LianTong_ContractApproveHistoryModels', @level2type=N'COLUMN',@level2name=N'CreateUserName'

--修改字段
ALTER TABLE CisEmployee ALTER COLUMN EmployeeDescription nvarchar(max) NULL;

sp_rename 'KYX_Employee.PK_KYX_Department_DepartmentName','PK_KYX_Department_DepartmentName1','column'

/*ALTER TABLE 删除字段 */
ALTER TABLE TABLE_USER DROP COLUMN TEMP_COL;

--按照字符串长度获取数据
SELECT [CompanyName]
      ,LEN(CompanyName) as lengths
  FROM [dbo].[OOF_Company]
  where LEN(CompanyName) <= 4

--按照字符串长度更新数据
update [dbo].[OOF_Company] set EnumCompanyStatus = '0'
  where LEN(CompanyName) <= 4

--查询当天数据
  SELECT * FROM 表 WHERE datediff(day,列名,getdate())=0

  --获取关联表的数据更新
  UPDATE QST_OrderDetail
   SET 
      ActualPrice = (SELECT CurrentPrice FROM QST_Product WHERE ID = QST_OrderDetail.PK_QST_Product_ProductName)

--一次性修改关联表的多个字段 
update [dbo].[FarmC_Equipment] 
set Province=b.Province,[City]=b.[City],[Village]=b.Village,Prefecture = b.Prefecture, Hamlet = b.Hamlet
from [FarmC_Equipment] a join FarmC_Cooperative b on a.PK_FarmC_Cooperative_CooperativeName=b.Id

--修改自增的初始值
DBCC CHECKIDENT ('TXCC_Assit', RESEED, 100000)

--Valuess((N.w*',)

    SELECT [Id]
      ,[Operator]
      ,[Message]
      ,[Result]
      ,[Type]
      ,[Module]
      ,[CreateTime]
  FROM [dbo].[SysLog]
  WHERE CreateTime >= Convert(datetime,'2018-05-02 17:20:00', 101)
  and CreateTime <= Convert(datetime,'2018-05-02 17:30:00', 101)

  update [GMGood] set [uploaddate] = REPLACE(SUBSTRING([uploaddate],6, 10),'.','-') where a=a

--字符串值的长度
      datalength(uploaddate) = 20

--字符串位置
Select CharIndex('a', '1235ab')
--5



SELECT * FROM (select row_number()over(order by uploaddate desc)rownumber,* from GMGood) GMGood1 
WHERE statusupload = '1' and rownumber between 31 and 60

SQL Server 字段设置默认值
1. 如果表字段已经建好
ALTER   TABLE   表名  ADD   CONSTRAINT   DF_TABLEName_FieldName   DEFAULT   1   FOR   字段名
2. 如果表字段没有建
alter table 表名 add 字段名 int default(1)

--修改表增加多字段唯一性校验，前提是这些个字段都必须是固定长度的，不能是nvarchar(max)了。
ALTER TABLE OA_Meeting ADD CONSTRAINT MeetingRoomTimeUni unique(PK_OA_MeetingRoom_RoomName,MeetingStart,MeetingEnd, EnumMeetingStatus,CancelSerialNo)