SQL 日期转换及复制表

1、日期函数dateadd进行加减年月日小时，拼接标准日期格式

1、set fldDate=Convert(date,dateadd(hour,-1,Convert(datetime,fldDate + ' ' +CONVERT(varchar(2),fldTime)+':00:00'))),fldTime=DATEPART(HOUR,dateadd(hour,-1,Convert(datetime,fldDate + ' ' +CONVERT(varchar(2),fldTime)+':00:00')))

 

2、len函数判断字符串长度有case  when then else end 进行填补日期类型

2、case  When len(fldMonth)=1 then '0'+convert(varchar(2),fldMonth) else convert(varchar(2),fldMonth) end

 

 3、根据一张表的内容复制到另一张表要写出所对应的字段重要，几个日期函数顺便提一下

3、insert into tblEQIA_RPI_Basedata (fldSTCode,fldPCode,fldSYear,fldSMonth,fldSDay,fldSHour,fldSMinute,fldEYear,fldEMonth,fldEDay,fldEHour,fldEMinute ,fldItemCode ,fldItemValue ,fldSource,fldUserID)
   select '210200',fldPCode,YEAR(F2),MONTH(F2),DAY(F2),0,0,YEAR(F2),MONTH(F2),DAY(F2),23,59,fldItemCode,F3,0,0 from dbo.Sheet1$
   inner join tblEQIA_R_Point on F1=fldSort 
   inner join tblEQIA_R_Item on F4=fldItemName 
　　where tblEQIA_R_Point.fldYear =2011

 

 4、删除表进行条件判断是否存在

4、delete   tblEQIP_S_CompanyInfo from tblEQIP_S_CompanyInfo T where   
exists(   
select 1  from  tblEQIP_S_CompanyInfo   where   fldMonitorYear=T.fldMonitorYear   and   fldDistrictCode=T.fldDistrictCode and  fldCompanyName=T.fldCompanyName 
and  fldAutoID < T.fldAutoID
)