SQL server 系统视图查询

-- 查询所有表名、字段名、类型、长度

select o.name, c.name,t.name,c.length from syscolumns c inner join systypes t on c.xtype= t.xtype inner join sysobjects o on c.id= o.id where o.xtype="u" order by o.name, c.name,t.name

-- 所有数据都来自于这四张表

--select * from sysobjects
--select * from syscolumns

--select * from syscomments

--select * from systypes

--列出数据库里所有的表名

SELECT name FROM sysobjects WHERE type = "U "

--列出表里的所有的列名

SELECT name FROM syscolumns WHERE id = OBJECT_ID("TableName ")

1 判断数据库是否存在

if exists (select * from sys.databases where name = "数据库名")
drop database [数据库名]

2 判断表是否存在

if exists (select * from sysobjects where id = object_id(N"[表名]") and OBJECTPROPERTY(id, N"IsUserTable") = 1)
drop table [表名]

3 判断存储过程是否存在

if exists (select * from sysobjects where id = object_id(N"[存储过程名]") and OBJECTPROPERTY(id, N"IsProcedure") = 1)
drop procedure [存储过程名]

4 判断临时表是否存在

if object_id("tempdb..#临时表名") is not null
drop table #临时表名

5 判断视图是否存在

--判断是否存在"MyView52"这个试图

IF EXISTS (SELECT TABLE_NAME FROM INFORMATioN_SCHEMA.VIEWS WHERE TABLE_NAME = N"MyView52") PRINT "存在" else PRINT "不存在"

6 判断函数是否存在 -- 判断要创建的函数名是否存在
if exists (select * from dbo.sysobjects where id = object_id(N"[dbo].[函数名]") and xtype in (N"FN", N"IF", N"TF"))
drop function [dbo].[函数名]

7 获取用户创建的对象信息

SELECT [name],[id],crdate FROM sysobjects where xtype="U"

8 判断列是否存在

if exists(select * from syscolumns where id=object_id("表名") and name="列名")
alter table 表名 drop column 列名

9 判断列是否自增列

if columnproperty(object_id("table"),"col","IsIdentity")=1
print "自增列"
else
print "不是自增列"

SELECT * FROM sys.columns WHERE object_id=OBJECT_ID("表名") AND is_identity=1

10 判断表中是否存在索引

if exists(select * from sysindexes where id=object_id("表名") and name="索引名")
print "存在"
else
print "不存在"

11 查看数据库中对象

SELECT * FROM sys.sysobjects WHERE name="对象名" SELECT * FROM sys.sysobjects WHERE name="对象名"