select object_id('名称') ,object_id('名称','类型')

1. 等价于 

select * from sys.objects where name ='名称'select * from sys.objects where name ='名称' and type ='类型'

2. 可用于判断表等是否存在

如：

if(OBJECT_ID('rdrecord','u') is not null)print '存在'elseprint '不存在'

3. 可返回sys.objects系统视图中的object_id的值 如果没有则返回null

4. sys.objects里有所有的数据库对像 如:表、视图、列、存储过程、函数、约束等等等等

5. 视了试图、表、存储过程类型明确的可用 object_id('名称'，'类型')判断。当然sql2008r2（以前版本未测试）一个数据库中的对像名是不能重复的所以也可只用对像名判断

别的类型可用类似方法

select * from sys.objects where object_id =object_id(N'DF__rdrecord__Sex__07020F21') and parent_object_id=object_id('表名','类型')select COL_LENGTH('表','列');--列的长度 判断列是否存在

 

6. 类型如下

V = View

U = Table (user-defined)

P = SQL Stored Procedure

AF = Aggregate function (CLR)

C = CHECK constraint

D = DEFAULT (constraint or stand-alone)

F = FOREIGN KEY constraint

FN = SQL scalar function

FS = Assembly (CLR) scalar-function

FT = Assembly (CLR) table-valued function

IF = SQL inline table-valued function

IT = Internal table

PC = Assembly (CLR) stored-procedure

PG = Plan guide

PK = PRIMARY KEY constraint

R = Rule (old-style, stand-alone)

RF = Replication-filter-procedure

S = System base table

SN = Synonym

SQ = Service queue

TA = Assembly (CLR) DML trigger

TF = SQL table-valued-function

TR = SQL DML trigger

UQ = UNIQUE constraint

X = Extended stored procedure

表中结构如下图