OBJECT_ID 有哪些種類

特別是在建表建存儲過程的時候進場會寫到:

IF OBJECT_ID('Table_Test','U') IS NOT NULL
DROP TABLE Table_Test

這種方式代替了以往所使用的

IF EXISTS (SELECT * FROM SYSOBJECTS WHERE NAME = 'Table_Test')
DROP TABLE Table_Test

第一段代碼中的 U 可以省略不寫, 這樣系統就會檢索所有的對象名稱以找到對應的ID, 但是寫出來就可以更加明確是哪一種類型,篩選的范圍要小很多.
以下列出全部 Object type (加粗的是比較常用的): 

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

TT = Table type

U = Table (user-defined)

UQ = UNIQUE constraint

V = View

X = Extended stored procedure

可以通過這個查詢語句獲取當前數據庫中各個數據庫表，視圖，存儲過程等數量。

SELECT CASE TYPE
               WHEN 'U'  THEN 'User Defined Tables'
               WHEN 'V'  THEN 'View' 
              WHEN 'S'  THEN 'System Tables'
               WHEN 'IT' THEN 'Internal Tables'
               WHEN 'P'  THEN 'Stored Procedures'
               WHEN 'PC' THEN 'CLR Stored Procedures'
               WHEN 'X'  THEN 'Extended Stored Procedures'
               WHEN 'FN' THEN 'Scalar-valued Functions'
               WHEN 'IF' THEN 'Table-valued Functions'
        END AS Objects,
        COUNT(*) AS Counts   
FROM SYS.OBJECTS
WHERE TYPE IN ('U','V','S','IT','P','PC','X','FN','IF')
GROUP BY TYPE