SQL Server checks whether a table exists (such as the table name, function, and stored procedure)

Source: Internet
Author: User

How to determine the existence of a table or database in SQL server, but in actual use, you need to determine the Status bit:
Some status bits can be set by the user using sp_dboption (read only, dbo use only, single user, etc:

1 = autoclose; Use sp_dboption to set. The database is completely closed, and its resources are released after the last user logs out.
4 = select into/bulkcopy; Use sp_dboption to set. The Select INTO statement and quick large-capacity replication are allowed.
8 = trunc. log on chkpt; Use sp_dboption to set. If the database is in log truncation mode, the check point truncates the non-active part of the log. This option can only be set for the master database. 16 = torn page detection, which is set using sp_dboption. Detect incomplete pages.
32 = loading.
64 = pre recovery.
128 = recovering.
256 = not recovered.
512 = offline; Use sp_dboption to set. The database is offline.
1024 = read only; Use sp_dboption. Users can only read data in the database and cannot modify it.
2048 = dbo use only; use sp_dboption to set. Only the database owner can use the database.
4096 = single user; Use sp_dboption to set. Only one user can access the database at a time.
32768 = emergency mode.
4194304 = autoshrink.
1073741824 = cleanly shutdown.

You can open multiple locations at the same time.

For example, determine whether a database is offline.
Select * From master. dbo. sysdatabases where name = 'pubs' and status <> 512

Check whether the table object exists in SQL Server:
Select count (*) from sysobjects where id = object_id ('database name. Owner. Table name ')

If exists
(Select count (*) from sysobjects where id = object_id ('database name. Owner. Table name '))
Print 'exist'
Else
Print 'nonexistent'

In SQL Server, check whether the fields in the table exist:
If exists (select * from syscolumns where name = 'colname1' and id = object_id ('database name. Owner. Table name '))
Print 'exist'
Else
Print 'nonexistent'
Indicates that the table tablename1 contains the colname1 field.
Example:
Select * from syscolumns where name = 'test' and id = object_id ('dbo. test ')

Access to determine whether the table object exists:
In fact, the Access database also has system tables and stores object names.
Select Count (*) AS Qty FROM MSysObjects Where (MSysObjects. Name) Like 'table name ');

Copy codeThe Code is as follows:
Whether the library exists
If exists (select * from master .. sysdatabases where name = N 'database name ')
Print 'exists'
Else
Print 'not exists'
---------------
-- Determine whether the table name to be created exists
If exists (select * from dbo. sysobjects where id = object_id (n' [dbo]. [Table name] ') and OBJECTPROPERTY (id, n'isusertable') = 1)
-- Delete a table
Drop table [dbo]. [table name]
GO
---------------
----- Whether the Column exists
IF COL_LENGTH ('table name', 'column name') IS NULL
PRINT 'not exists'
ELSE
PRINT 'exists'
Alter table Name drop constraint default name
Go
Alter table Name drop column name
Go
-----
-- Determine whether the temporary table to be created exists
If Object_Id ('tempdb. dbo. # test') Is Not Null
Begin
Print 'exist'
End
Else
Begin
Print 'nonexistent'
End
---------------
-- Determine whether the stored procedure name to be created exists
If exists (select * from dbo. sysobjects where id = object_id (n' [dbo]. [stored procedure name] ') and OBJECTPROPERTY (id, n' IsProcedure') = 1)
-- Delete a stored procedure
Drop procedure [dbo]. [stored procedure name]
GO
---------------
-- Determine whether the view name to be created exists
If exists (select * from dbo. sysobjects where id = object_id (n' [dbo]. [view name] ') and OBJECTPROPERTY (id, n'isview') = 1)
-- Delete View
Drop view [dbo]. [view name]
GO
---------------
-- Determine whether the name of the function to be created exists
If exists (select * from sysobjects where xtype = 'fn 'and name = 'function name ')
If exists (select * from dbo. sysobjects where id = object_id (n' [dbo]. [function name] ') and xtype in (n'fn', n'if', n'tf '))
-- Delete a function
Drop function [dbo]. [function name]
GO
If col_length ('table name', 'column name') is null
Print 'nonexistent'
Select 1 from sysobjects where id in (select id from syscolumns where name = 'column name') and name = 'table name'

Related Article

Contact Us

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: info-contact@alibabacloud.com and provide relevant evidence. A staff member will contact you within 5 working days.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.