Attach or detach content databases in SharePoint Server
APPLIES TO: 
2013 2016 2019 Subscription Edition 
SharePoint in Microsoft 365
You can attach or detach SharePoint Server content databases by using the SharePoint Central Administration website or Microsoft PowerShell
Before you begin
Before you begin this operation, review the following information:
If you want to create a new content database while you attach it, the SharePoint farm service account must be a member of the SQL Server dbcreator fixed server role. To attach a content database to a web application, the SharePoint farm service account must have db_owner permission for the content database.
If the database already exists, it must be the same version as the SharePoint Server 2016 farm or this operation will fail. To attach a content database that is a different version than the farm, use the To attach or detach a content database by using Windows PowerShell procedure in the following section.
Attaching and detaching content databases
You might want to attach or detach content databases for the following reasons. You want to add a new content database for new site collections to keep content databases at a manageable size. You are restoring a content database from another farm and you want the sites that it contains to be accessed from a web application. You have archived site collections out of a content database and then detach the content database from the web application. For more information, see Move site collections between databases in SharePoint Server
The steps to add a database and to attach a database are very similar. For more information about how to add a database, see Add content databases in SharePoint Server.
To attach a content database by using Central Administration
Verify that the user account that is being used to perform this operation is a member of the Farm Administrators SharePoint group.
Start Central Administration.
On the SharePoint Central Administration website, click Application Management.
On the Application Management page, in the Databases section, click Manage content databases.
On the Manage Content Databases page, click Add a content database.
On the Add Content Database page:
Use the Web Application drop-down menu to select the web application to which you want to attach a content database.
Specify the database server that hosts the database.
Specify the database name. If the database does not already exist, it will be created.
Specify the authentication method for the database, and supply an account name and password if you are using SQL authentication.
Note
The account name and password must already exist as a SQL Server login. We recommend that you use Windows authentication instead of SQL authentication because, by default, SQL authentication sends a nonencrypted password to the computer that is running SQL Server. If you use SQL authentication, the SQL account requires the same SQL permissions as the SharePoint farm service account.
Click OK.
To detach a content database by using Central Administration
Verify that the user account that is performing this procedure is a member of the Farm Administrators SharePoint group.
On the SharePoint Central Administration website, click Application Management.
On the Application Management page, in the Databases section, click Manage content databases.
Select the web application for which you want to detach a content database.
Click the content database that you want to detach.
On the Manage Content Database Settings page, select the Remove content database check box.
If the content database contains data, you will receive a warning. Click OK to continue with the operation.
Click OK to confirm the detachment, or click Cancel to stop the operation without detaching the database.
After detaching the content database in Central Administration, the content database still exists in SQL Server. If you want to permanently remove the content database, you must do so by using a SQL Server procedure.
To attach or detach a content database by using PowerShell
- Verify that you have the following memberships:
securityadmin fixed server role on the SQL Server instance.
db_owner fixed database role on all databases that are to be updated.
Administrators group on the server on which you are running the PowerShell cmdlets.
An administrator can use the Add-SPShellAdmin cmdlet to grant permissions to use SharePoint Server cmdlets.
Note
If you do not have permissions, contact your Setup administrator or SQL Server administrator to request permissions. For additional information about PowerShell permissions, see Add-SPShellAdmin.
Open SharePoint Management Shell.
At the PowerShell command prompt, type the appropriate command
To attach an existing content database:
Mount-SPContentDatabase "<ContentDb>" -DatabaseServer "<DbServer>" -WebApplication http://SiteNameWhere:
<ContentDb> is the content database to be attached.
<DbServer> is the name of the database server.
http://SiteName is the name of the web application to which the content database is being attached.
To detach a content database:
Dismount-SPContentDatabase "<ContentdBName>"Where <ContentdBName> is the name of the content database.
Important
If you have multiple content databases that have the same name, you must use the content database GUID in this command instead of using the content database name. To retrieve the GUID of the content database, run the Get-SPContentDatabase cmdlet with no arguments.
The Dismount-SPContentDatabase cmdlet detaches the content database from the web application, but it does not delete the content database from SQL Server. After a content database is detached, you cannot delete it by using PowerShell. You can only remove it by using SQL Server tools. If you want to delete the content database from SQL Server while you detach it, use the Remove-SPContentDatabase cmdlet instead.
For more information, see Dismount-SPContentDatabase and Mount-SPContentDatabase.
Note
We recommend that you use Microsoft PowerShell when performing command-line administrative tasks. The Stsadm command-line tool has been deprecated, but is included to support compatibility with previous product versions.