• 使用系统表之批量规范外键命名


    设计数据库时,规范命名是一项不可或缺的任务。但是我们现在习惯于企业管理器的鼠标操作,很多时候我们都是用了系统的缺省命名。然而,作为正规的开发我们还是想规范他们的命名,由此我就想到了系统表中存放了所有数据库对象的信息,我们既可以利用Sql 读取他们 也可以根据他们 修改已有数据!

    以外键为例,首先我们到数据库中查询一下所有的外键信息吧

    /*------------------------------- 查询当前库中所有的外键信息 ------------------------------*/

    select b.name as fkName, c.tName as fTableName, c.colName, d.tName as rTableName, d.colName
    from SysForeignkeys as a
     join SysObjects as b on a.constid = b.id
     join (
      select a.id as tID, a.name as tName, b.colID, b.name as colName
      from SysObjects as a
       join SysColumns as b on a.id = b.id
     ) as c on a.fkeyid = c.tID and a.fkey = c.colID
     join (
      select a.id as tID, a.name as tName, b.colID, b.name as colName
      from SysObjects as a
       join SysColumns as b on a.id = b.id
     ) as d on a.rkeyid = d.tID and a.rkey = d.colID

    go

     既然我们能将当前外键信息查出,那么我们只要对查询结果稍加处理就可以实现我们的想法了!

    以下是我的具体实现代码,外键命名规范为 fk 开头然后是 关联表表名、外键字段名、被关联表表名、被关联表主键字段名称,中间以 两个下划线( “__”)连接。

    /*------------------------- 生成更改当前库外键名称的Sql -----------------------------*/

    select 'sp_rename '
     + nchar(39) + b.name + nchar(39)
     + ', '
     + nchar(39) + 'fk__'
     + c.tName + '__'
     + c.colName + '__'
     + d.tName + '__'
     + d.colName + nchar(39) as sql,
     identity(int, 1, 2) as id into #t1
    from SysForeignkeys as a
     join SysObjects as b on a.constid = b.id
     join (
      select a.id as tID, a.name as tName, b.colID, b.name as colName
      from SysObjects as a
       join SysColumns as b on a.id = b.id
     ) as c on a.fkeyid = c.tID and a.fkey = c.colID
     join (
      select a.id as tID, a.name as tName, b.colID, b.name as colName
      from SysObjects as a
       join SysColumns as b on a.id = b.id
     ) as d on a.rkeyid = d.tID and a.rkey = d.colID

    go

    select 'go' as sql, identity(int, 2, 2) as id into #t2
    from #t1
    go

    select sql
    from (
     select * from #t1
     union
     select * from #t2
    ) as t
    order by id
    go

    drop table #t1
    go
    drop table #t2
    go

    将查询的结果 再执行一次就会实现我们想看到的结果!

  • 相关阅读:
    例20:希尔排序
    例19:直接插入排序
    例14:计算某日是该年的第几天
    为自己
    hdoj--1027--Ignatius and the Princess II(dfs)
    UESTC--758--P酱的冒险旅途(模拟)
    nyoj--990--蚂蚁感冒(模拟)(思维题)
    历届试题 邮局(dfs+剪枝)
    历届试题 数字游戏
    历届试题 回文数字
  • 原文地址:https://www.cnblogs.com/zhaoguan_wang/p/874757.html
Copyright © 2020-2023  润新知