• sql语句查询数据库中的表名/列名/主键/自动增长值


    原文地址:http://blog.csdn.net/pukuimin1226/article/details/7687538

    ----查询数据库中用户创建的表
    ----jsj01 为数据库名

    select name tablename from jsj01..sysobjects where type='U' and name not in ('dtproperties')

    --查询表里的字段信息

    exec sp_help  对象名

    ---docs为表名

    select * from syscolumns where id = object_id('docs')

    ----查询数据库中所有类型

    select name,xtype from systypes

    ----两表联查,显示表中所有字段和对应的数据类型
    ----syscolumns里字段‘xtype’ 对应 systypes里的 ‘xusertype’ ,systypes 里的‘name’字段就是字段的数据类型
    ----docs 为表名

    select a.name as fieldname,b.name as type from 
    syscolumns as a 
    join systypes as b 
    on a.xtype = b.xusertype 
    where id=object_id('docs')

    ----docs为数据表名   : 查询表字段、类型、说明

    select a.name  fieldname,b.name  type,c.value comment from 
    syscolumns as a 
    full join systypes as b 
    on a.xtype = b.xusertype
    full join ::fn_listextendedproperty(NULL, 'user', 'dbo', 'table', 'docs', 'column', default) as c ----这是2000版本,2005把user改为schema
    on a.name=c.objname COLLATE Chinese_PRC_CI_AS  -----排序规则(有时不加也可以,如果两表的排序规则不同,则会报错)
    --join sysproperties c
    --on a.id=c.major_id
    where id=object_id('docs')

    ----查询表里的主键,没有主键为空,如果是多个组合主键就有多个值  pk为主键  fk为外键
    --- jsj01 为数据库名  docs为表名  fk表示外键 

    ----sql2000

    select column_name as primarykey,*  from 
    [jsj01].INFORMATION_SCHEMA.KEY_COLUMN_USAGE 
    where Table_name='docs' and constraint_name like 'fk_%'

    -----sql2005

    SELECT @PrimaryKey =  CCU.COLUMN_NAME
    FROM     INFORMATION_SCHEMA.TABLE_CONSTRAINTS TC 
        INNER JOIN INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE CCU ON TC.CONSTRAINT_NAME = CCU.CONSTRAINT_NAME
    WHERE TC.TABLE_NAME = 'docs' AND TC.CONSTRAINT_TYPE='PRIMARY KEY'
    --select * from sysobjects WHERE OBJECT_NAME(sysobjects.parent_obj)='docs' --and xtype='pk'
    --select * from sysconstraints  where id = object_id('docs')
    --select * from syscolumns where id = object_id('docs')
    --select * from sysindexes 
    --select * from sysindexkeys

    ----查询表中自动增长的字段,没有为空,如果有就只有一个
    ----docs为表名  -- sql2000

    SELECT a.name column_name,b.name  data_type
    FROM syscolumns a,systypes b
    WHERE a.id=object_id('docs') and a.xtype = b.xusertype 
    AND a.autoval is not null

    -------- sql2005

    select 
        a.Name
    from 
        syscolumns a 
    left join
        sysobjects b on a.iD=b.parent_obj and b.xtype='PK'
    where
        a.ID=object_id('docs') and a.status=0x80

    ----For mssql2005

    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, 
    标识=case when COLUMNPROPERTY(a.id,a.name,'IsIdentity')=1 then '1' 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 '1' 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 '1' else '' end,
    默认值=isnull(e.text,''),
    字段说明=isnull(g.[value],'')
    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 sys.extended_properties g on a.id=g.major_id and a.colid=g.minor_id 
    left join sys.extended_properties f on d.id=f.major_id and f.minor_id =0 
    --where d.name='classinfo'         --如果只查询指定表,加上此条件   
    order by a.id,a.colorder

    ----For mssql2000

    SELECT 
    表名=d.name,--case when a.colorder=1 then d.name else '' end,
    字段序号=a.colorder,
    字段名=a.name,
    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,''),
    字段说明=isnull(g.[value],'')
    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 
    order by a.id,a.colorder

     

  • 相关阅读:
    【[CQOI2015]选数】
    杜教筛
    【[CQOI2009]跳舞】
    【简单的数学题】
    【[SDOI2013]泉】
    【[AHOI2013]差异】
    【[HEOI2016/TJOI2016]序列】
    【[SDOI2008]Sandy的卡片】
    linux系统编程之信号(一)
    linux系统编程之进程(五)
  • 原文地址:https://www.cnblogs.com/jiyang2008/p/6085635.html
Copyright © 2020-2023  润新知