SQL Server 基础知识回顾

背景：工作调整，由mysql转到sql server，从今天开始学习，进行知识储备。

1. sql server查询数据库表结构说明

   -- 数据字典
   SELECT
           (case when a.colorder=1 then d.name else '' end)表名,
           a.colorder 字段序号,
           a.name 字段名,
           (case when COLUMNPROPERTY( a.id,a.name,'IsIdentity')=1 then '√'else '' end) 标识,
          (case when (SELECT count(*)
           FROM sysobjects
           WHERE (name in
                   (SELECT name
                   FROM sysindexes
                   WHERE (id = a.id) AND (indid in
                            (SELECT indid
                           FROM sysindexkeys
                           WHERE (id = a.id) AND (colid in
                                     (SELECT colid
                                    FROM syscolumns
                                    WHERE (id = a.id) AND (name = a.name))))))) AND
               (xtype = 'PK'))>0 then '√' else '' end) 主键,
          b.name 类型,
          a.length 占用字节数,
         COLUMNPROPERTY(a.id,a.name,'PRECISION') as 长度,
         isnull(COLUMNPROPERTY(a.id,a.name,'Scale'),0) as 小数位数,
         (case when a.isnullable=1 then '√'else '' end) 允许空,
         isnull(e.text,'') 默认值,
         isnull(g.[value],'') AS 字段说明
   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.major_id
   order by a.id,a.colorder,表名