請問: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]')是什麼意思?那個object_id函數?那個N? 還有OBJECTPROPERTY(id, N'IsUserTable') = 1中的OBJECTPROPERTY函數是什麼意思?那個=1又是什麼意思? OBJECT_ID:傳回資料庫對象辨別号。N是顯式的将非unicode字元轉成unicode字元,它來自 SQL-92 标準中的 National(Unicode)資料類型,用于擴充和标準化,在這裡可以不用,寫作object_id(PerPersonData)。 OBJECTPROPERTY:傳回目前資料庫中對象的有關資訊。1表“真”。同樣可以寫成OBJECTPROPERTY(id, sUserTable) = 1。 整條語句的意思是判斷資料庫裡有沒有存在PerPersonData這樣一張表。 ===================================================================== 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');各部分什麼意思?誰能解釋下? 答案:sys.ojects是一張表名 oject_id是取對象的ID N表示使用Union Code,防止亂碼。 ================================================================================== 3. OBJECT_ID ('student', 'U')是什麼意思 在SQL裡 IF OBJECT_ID ('student', 'U') IS NOT NULL U 是什麼意思 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 |