sql点滴

子表查询，父表一定要加别名，否则数据会有问题，不报编译错
select * from table1 a where exist(select 1 from table2 where a.id=b.id)
存储过程结果集插入到现有表
insert into table1 exec procname args
联合已有表，紧跟在后面，对汇总很有用
select a from table1 union all select '合计'
结果集里的某列相加
declare @var nvarchar(1000)
set @var=''
select @var=@var+','+alarmname from notice where args=@args
print @var
shell命令
declare @cmd nvarchar(1000)
set @cmd='bcp "select cellphone,msg from atm.dbo.sendoutmsg" queryout '+@outfile+' -c -q -t "|"  -U'+@sqluser+' -P'+@sqlpwd +' -S'+@server
EXEC master..xp_cmdshell    @cmd    ,NO_OUTPUT
(
@cmd 可以是：
dir    c:\      c:\dir_out.txt
del   c:\deposit.htm
copy   c:\resource\deposit.htm    c:\
move   c:\倒入0911.xls    d:\倒入0911.xls
)
大容量数据导入(以\r\n为数据行结尾,|为列分割符)
DECLARE @bulk_cmd varchar(1000);
SET @bulk_cmd = 'BULK INSERT dbo.tmpbasedevinfo from ''D:\dev_bmsg.txt''
                             with (FIELDTERMINATOR =''|'',
                                      ROWTERMINATOR = '''+CHAR(10)+''')';
exec(@bulk_cmd);
判断文件是否存在
create table #tb(a bit,b bit,c bit)  
  insert into #tb exec master..xp_fileexist 'c:\furniture.txt'
  if exists(select * from #tb where a=1)
  PRINT 文件存在
  else
  PRINT 文件不存在
drop table #tb