sp_attach_db (Transact-SQL)
Applies to: 
SQL Server
Attaches a database to a server.
Important
This feature will be removed in a future version of SQL Server. Avoid using this feature in new development work, and plan to modify applications that currently use this feature. We recommend that you use CREATE DATABASE <database_name> FOR ATTACH instead. For more information, see CREATE DATABASE. To rebuild multiple log files when one or more have a new location, use CREATE DATABASE <database_name> FOR ATTACH_REBUILD_LOG.
Don't attach or restore databases from unknown or untrusted sources. Such databases could contain malicious code that might execute unintended Transact-SQL code or cause errors by modifying the schema or the physical database structure. Before you use a database from an unknown or untrusted source, run DBCC CHECKDB on the database on a nonproduction server and also examine the code, such as stored procedures or other user-defined code, in the database.
Syntax
sp_attach_db
[ @dbname = ] N'dbname'
, [ { @filename1 ... @filename16 } = ] { N'*filename1*' ... N'*filename16*' }
[ ; ]
Arguments
[ @dbname = ] N'dbname'
The name of the database to be attached to the server. @dbname is sysname, with no default.
[ { @filename1 ... @filename16 } = ] { N'filename1' ... N'filename16' }
The physical name, including path, of a database file. This parameter is nvarchar(260), with a default of NULL. You can specify up to 16 file names. The parameter names start at @filename1 and increment to @filename16. The file name list must include at least the primary file (.mdf). The primary file contains the system tables that point to other files in the database. The list must also include any files that were moved after the database was detached.
This parameter maps to the FILENAME parameter of the CREATE DATABASE statement. For more information, see CREATE DATABASE.
Note
When you attach a SQL Server 2005 (9.x) database that contains full-text catalog files onto a newer version of SQL Server, the catalog files are attached from their previous location along with the other database files, the same as in SQL Server 2005 (9.x). For more information, see Upgrade Full-Text Search.
Return code values
0 (success) or 1 (failure).
Result set
None.
Remarks
The sp_attach_db stored procedure should only be executed on databases that were previously detached from the database server by using an explicit sp_detach_db operation or on copied databases. If you have to specify more than 16 files, use CREATE DATABASE <database_name> FOR ATTACH or CREATE DATABASE <database_name> FOR_ATTACH_REBUILD_LOG. For more information, see CREATE DATABASE.
Any unspecified file is assumed to be in its last known location. To use a file in a different location, you must specify the new location.
A database created by a more recent version of SQL Server can't be attached in earlier versions.
Note
A database snapshot can't be detached or attached.
When you attach a replicated database that was copied instead of being detached, consider the following conditions:
If you attach the database to the same server instance and version as the original database, no further steps are required.
If you attach the database to the same server instance but with an upgraded version, you must execute sp_vupgrade_replication to upgrade replication after the attach operation is complete.
If you attach the database to a different server instance, regardless of version, you must execute sp_removedbreplication to remove replication after the attach operation is complete.
When a database is first attached or restored to a new instance of SQL Server, a copy of the database master key (DMK) - encrypted by the service master key (SMK) - isn't yet stored in the server. You must use the OPEN MASTER KEY statement to decrypt the DMK. Once the DMK has been decrypted, you have the option of enabling automatic decryption in the future by using the ALTER MASTER KEY REGENERATE statement to provide the server with a copy of the DMK, encrypted with the SMK. When a database is upgraded from an earlier version, the DMK should be regenerated to use the newer AES algorithm. For more information about regenerating the DMK, see ALTER MASTER KEY. The time required to regenerate the DMK key to upgrade to AES depends upon the number of objects protected by the DMK. Regenerating the DMK key to upgrade to AES is only necessary once, and has no effect on future regenerations as part of a key rotation strategy.
Permissions
For information about how permissions are handled when a database is attached, see CREATE DATABASE.
Examples
The following example attaches files from AdventureWorks2022 to the current server.
EXEC sp_attach_db @dbname = N'AdventureWorks2022',
@filename1 =
N'C:\Program Files\Microsoft SQL Server\MSSQL13.MSSQLSERVER\MSSQL\Data\AdventureWorks2022_Data.mdf',
@filename2 =
N'C:\Program Files\Microsoft SQL Server\MSSQL13.MSSQLSERVER\MSSQL\Data\AdventureWorks2022_log.ldf';