Check if table exists in SQL Server

2018-12-31 07:14发布

I would like this to be the ultimate discussion on how to check if a table exists in SQL Server 2000/2005 using SQL Statements.

When you Google for the answer, you get so many different answers. Is there an official/backward and forward compatible way of doing it?

Here are two possible ways of doing it. Which one among the two is the standard/best way of doing it?

First way:

IF EXISTS (SELECT 1 
           FROM INFORMATION_SCHEMA.TABLES 
           WHERE TABLE_TYPE='BASE TABLE' 
           AND TABLE_NAME='mytablename') 
   SELECT 1 AS res ELSE SELECT 0 AS res;

Second way:

IF OBJECT_ID (N'mytablename', N'U') IS NOT NULL 
   SELECT 1 AS res ELSE SELECT 0 AS res;

MySQL provides the simple

SHOW TABLES LIKE '%tablename%'; 

statement. I am looking for something similar.

22条回答
琉璃瓶的回忆
2楼-- · 2018-12-31 07:19
IF EXISTS 
(
    SELECT   * 
    FROM     sys.objects 
    WHERE    object_id = OBJECT_ID(N'[dbo].[Mapping_APCToFANavigator]') 
             AND 
             type in (N'U')
)
BEGIN

    -- Do whatever you need to here.

END

Here in the above code, the table name is Mapping_APCToFANavigator.

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墨雨无痕
3楼-- · 2018-12-31 07:20
select name from SysObjects where xType='U' and name like '%xxx%' order by name
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与君花间醉酒
4楼-- · 2018-12-31 07:24

consider in one database you have a table t1. you want to run script on other Database like - if t1 exist then do nothing else create t1. To do this open visual studio and do the following:

Right click on t1, then Script table as, then DROP and Create To, then New Query Editor

you will find your desired query. But before executing that script don't forget to comment out the drop statement in the query as you don't want to create new one if there is already one.

Thanks

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初与友歌
5楼-- · 2018-12-31 07:25

I know it is an old question but I have found this possibility if you plan to call it often.

create procedure Table_Exists
@tbl varchar(50)
as
return (select count(*) from sysobjects where type = 'U' and name = @tbl)
go
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妖精总统
6楼-- · 2018-12-31 07:32

Using the Information Schema is the SQL Standard way to do it, so it should be used by all databases that support it.

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十年一品温如言
7楼-- · 2018-12-31 07:32

Just adding here, for the benefit of developers and fellow DBAs

a script that receives @Tablename as a parameter

(which may or may not contain the schemaname) and returns the info below if the schema.table exists:

the_name                object_id   the_schema  the_table       the_type
[Facts].[FactBackOrder] 758293761   Facts       FactBackOrder   Table

I produced this script to be used inside other scripts every time I need to test whether or not a table or view exists, and when it does, get its object_id to be used for other purposes.

It raises an error when either you passed an empty string, wrong schema name or wrong table name.

this could be inside a procedure and return -1 for example.

As an example, I have a table called "Facts.FactBackOrder" in one of my Data Warehouse databases.

This is how I achieved this:

PRINT 'THE SERVER IS ' + @@SERVERNAME
--select db_name()
PRINT 'THE DATABASE IS ' + db_NAME() 
PRINT ''
GO

SET NOCOUNT ON
GO

--===================================================================================
-- @TableName is the parameter
-- the object we want to deal with (it might be an indexed view or a table)
-- the schema might or might not be specified
-- when not specified it is DBO
--===================================================================================

DECLARE @TableName SYSNAME

SELECT @TableName = 'Facts.FactBackOrder'
--===================================================================================
--===================================================================================
DECLARE @Schema SYSNAME
DECLARE @I INT
DECLARE @Z INT 

SELECT @TableName = LTRIM(RTRIM(@TableName))
SELECT @Z = LEN(@TableName)

IF (@Z = 0) BEGIN

            RAISERROR('Invalid @Tablename passed.',16,1)

END 

SELECT @I = CHARINDEX('.',@TableName )
--SELECT @TableName ,@I

IF @I > 0 BEGIN

        --===================================================================================
        -- a schema and table name have been passed
        -- example Facts.FactBackOrder 
        -- @Schema = Fact
        -- @TableName = FactBackOrder
        --===================================================================================

   SELECT @Schema    = SUBSTRING(@TABLENAME,1,@I-1)
   SELECT @TableName = SUBSTRING(@TABLENAME,@I+1,@Z-@I)



END
ELSE BEGIN

        --===================================================================================
        -- just a table name have been passed
        -- so the schema will be dbo
        -- example Orders
        -- @Schema = dbo
        -- @TableName = Orders
        --===================================================================================

   SELECT @Schema    = 'DBO'     


END

        --===================================================================================
        -- Check whether the @SchemaName is valid in the current database
        --===================================================================================

IF NOT EXISTS ( SELECT * FROM INFORMATION_SCHEMA.SCHEMATA K WHERE K.[SCHEMA_NAME] = @Schema ) BEGIN

            RAISERROR('Invalid Schema Name.',16,1)

END 

--SELECT @Schema  as [@Schema]
--      ,@TableName as [@TableName]


DECLARE @R1 TABLE (

   THE_NAME SYSNAME
  ,THE_SCHEMA SYSNAME
  ,THE_TABLE SYSNAME
  ,OBJECT_ID INT
  ,THE_TYPE SYSNAME
  ,PRIMARY KEY CLUSTERED (THE_SCHEMA,THE_NAME)

)

;WITH RADHE_01 AS (
SELECT QUOTENAME(SCHEMA_NAME(O.schema_id)) + '.' + QUOTENAME(O.NAME) AS [the_name]
      ,the_schema=SCHEMA_NAME(O.schema_id)
      ,the_table=O.NAME
      ,object_id =o.object_id 
      ,[the_type]= CASE WHEN O.TYPE = 'U' THEN 'Table' ELSE 'View' END 
from sys.objects O
where O.is_ms_shipped = 0
AND O.TYPE IN ('U','V')
)
INSERT INTO @R1 (
   THE_NAME 
  ,THE_SCHEMA 
  ,THE_TABLE 
  ,OBJECT_ID
  ,THE_TYPE 
)
SELECT  the_name
       ,the_schema
       ,the_table
       ,object_id
       ,the_type
FROM RADHE_01
WHERE the_schema = @Schema 
  AND the_table  = @TableName

IF (@@ROWCOUNT = 0) BEGIN 

             RAISERROR('Invalid Table Name.',16,1)

END 
ELSE BEGIN

    SELECT     THE_NAME 
              ,THE_SCHEMA 
              ,THE_TABLE 
              ,OBJECT_ID
              ,THE_TYPE 

    FROM @R1

END 
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