--1、返回数据库中所有表及字段的信息
SELECT 
    表名=case when a.colorder=1 then d.name else '' end,
    表说明=case when a.colorder=1 then isnull(f.value,'') else '' end,
    字段序号=a.colorder,
    字段名=a.name,
    字段标题=isnull(g.[value],''),
    标识=case when COLUMNPROPERTY( a.id,a.name,'IsIdentity')=1 then '√'else '' end,
    主键=case when 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
        ))) then '√' else '' end,
    类型=b.name,
    占用字节数=a.length,
    长度=COLUMNPROPERTY(a.id,a.name,'PRECISION'),
    小数位数=isnull(COLUMNPROPERTY(a.id,a.name,'Scale'),0),
    允许空=case when a.isnullable=1 then '√'else '' end,
    默认值=isnull(e.text,'')
--into ##tx
FROM syscolumns a
    left join systypes b on a.xtype=b.xusertype
    inner join sysobjects d on a.id=d.id  and d.xtype='U' and  d.name<>'dtproperties'
    left join syscomments e on a.cdefault=e.id
    left join sysproperties g on a.id=g.id and a.colid=g.smallid  
    left join sysproperties f on d.id=f.id and f.smallid=0
--where d.name='c_bg'    --如果只查询指定表,加上此条件
order by object_name(a.id),a.colorder