[ GROUP BY [ ALL ] group_by_expression [ ,...n ]
    [ WITH { CUBE | ROLLUP } ]
] 

长度与分析用

datalength(Char_expr) 返回字符串包含字符数,但不包含后面的空格

substring(expression,start,length) 不多说了,取子串

right(char_expr,int_expr) 返回字符串右边int_expr个字符

字符操作类

upper(char_expr) 转为大写

lower(char_expr) 转为小写

space(int_expr) 生成int_expr个空格

replicate(char_expr,int_expr)复制字符串int_expr次

reverse(char_expr) 反转字符串

stuff(char_expr1,start,length,char_expr2) 将字符串char_expr1中的从

start开始的length个字符用char_expr2代替

ltrim(char_expr) rtrim(char_expr) 取掉空格

ascii(char) char(ascii) 两函数对应,取ascii码,根据ascii吗取字符

字符串查找

charindex(char_expr,expression) 返回char_expr的起始位置

patindex("%pattern%",expression) 返回指定模式的起始位置,否则为0

SELECT SysObjects.Name as tb_name, SysColumns.Name as col_name, SysTypes.Name as col_type, SysColumns.Length as col_len, isnull(SysProperties.Value,SysColumns.Name) as col_memo,
case when SysColumns.name in
(select 主键=a.name
FROM syscolumns a
 inner join sysobjects b on a.id=b.id   and b.xtype='U' and  b.name<>'dtproperties'
 where   exists(SELECT 1 FROM sysobjects where xtype='PK' and name in (
  SELECT name FROM sysindexes WHERE indid in(
   SELECT indid FROM sysindexkeys WHERE id = a.id AND colid=a.colid
  )))
and  b.name=SysObjects.Name
)
 then 1 else 0 end as is_key

 FROM SysObjects,SysTypes,SysColumns
LEFT JOIN SysProperties ON (Syscolumns.Id = Sysproperties.Id AND
 Syscolumns.Colid = Sysproperties.Smallid)

 WHERE (Sysobjects.Xtype ='u' OR Sysobjects.Xtype ='v')
AND Sysobjects.Id = Syscolumns.Id AND SysTypes.XType = Syscolumns.XType
AND SysTypes.Name <> 'sysname' AND Sysobjects.Name Like '%' ORDER By SysObjects.Name, SysColumns.colid

如果只想操作一个表的，那么把最后的％换成表名就可以了。