OBJECT_ID & OBJECTPROPERTY

一.OBJECT_ID

返回数据库对象标识号。

语法

OBJECT_ID ( 'object' )

例如：USE master

SELECT OBJECT_ID('pubs..authors')

查看pubs数据库里的authors表的object_id。

二.OBJECTPROPERTY

返回当前数据库中对象的有关信息。

语法

OBJECTPROPERTY ( id , property )

例如：OBJECTPROPERTY ( object_id('authors'),'ISTABLE') = 1

判断authors对象是否是一个表。

在查询器里输入： 

use dye
       select objectproperty(object_id('dbo.arranging'),'IsUserTable') 

--------------------------
结果：（所影响的行数为 1 行）



======================================================================================== 
1.object_id(N'表名')



请问：if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[PerPersonData]') and OBJECTPROPERTY(id, N'IsUserTable') = 1)

中的object_id(N'[dbo].[PerPersonData]')是什么意思？那个object_id函数？那个N？

还有OBJECTPROPERTY(id, N'IsUserTable') = 1中的OBJECTPROPERTY函数是什么意思？那个＝1又是什么意思？

OBJECT_ID：返回数据库对象标识号。N是显式的将非unicode字符转成unicode字符，它来自 SQL-92 标准中的 National（Unicode）数据类型，用于扩展和标准化，在这里可以不用，写作object_id(PerPersonData)。

OBJECTPROPERTY：返回当前数据库中对象的有关信息。1表“真”。同样可以写成OBJECTPROPERTY(id, sUserTable) = 1。

整条语句的意思是判断数据库里有没有存在PerPersonData这样一张表。

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2.SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[#TEMPID1]') AND type in (N'U')


sys.objects ,OBJECT_ID(N'[dbo].[#TEMPID1]'); type in (N'U');各部分什么意思?谁能解释下?



答案：sys.ojects是一张表名

           oject_id是取对象的ID

          N表示使用Union Code，防止乱码。

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3. OBJECT_ID ('student', 'U')是什么意思 在SQL里


IF OBJECT_ID ('student', 'U') IS NOT NULL U 是什么意思 

OBJECT_ID ( '[ database_name . [ schema_name ] . | schema_name . ] 
       object_name' [ ,'object_type' ] )


Object type:
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
P = SQL Stored Procedure
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 
U = Table (user-defined)
UQ = UNIQUE constraint
V = View
X = Extended stored procedure