How to: Create a Snapshot of a Project
A Data-tier Application file provides you with a read-only representation of the database schema at the time it is created. It is essentially being treated as a database schema from which you can import the schema objects back to a project. You can also compare it with the schema of a database or a project, and update the database or project to reflect the schema defined in the snapshot.
In the event of a user error on a source database project, you can revert the source project to the state it was in when the snapshot was created. You can also establish snapshots at various stages of your development for baseline purpose.
To create a snapshot
Right-click the TradeDev project in Solution Explorer, and select Data-tier Application (*.dacpac)….
SSDT will attempt to build the project first. If there is no build error, a Snapshot folder is created in Solution Explorer. Inside this folder, SSDT creates a .dacpac file using the name format of “<Project Name>_YYYYMMDD_HH-MM-SS.dacpac”.
Right-click the .dacpac file and select Rename. Change the default file name to “TradeDev1.dacpac”.
Right-click the GetProductsBySupplier function in Solution Explorer and select Delete to remove it from the project.
Follow the previous steps to create a new snapshot called TradeDev2.dacpac.
To import a snapshot
Right-click the TradeDev project in Solution Explorer, select Import, then Data-tier Application (*.dacpac)… from the contextual menus.
In the Import Data-tier Application dialog box, click Browse to select TradeDev1.dacpac to be used as the source of the import.
Notice that the Target project section has been disabled, since the current project is the default target. Click Start to start the import.
Click Finish in the Summary page. In Solution Explorer, notice that the deleted table has been restored to the project.
The import snapshot will import all database entities in the snapshot schema to the project. This might create duplicate entities as a result. For example, each of the tables and view now contains an additional copy of itself named <ObjectName_1>. Right-click each of these duplicate objects in Solution Explorer and select Delete to remove it from the project.
To compare snapshots
Right-click TradeDev1.dacpac in Solution Explorer and select Schema Compare. The Schema Compare window opens.
Use the Data-tier Application File options to set the source and target schemas. Make sure that the Source Schema is set to TradeDev1.dacpac in Data-tier Application File, and the Target Schema is set to TradeDev2.dacpac.
Click OK to start the compare. Notice that the deleted function is being highlighted as a difference between the old and new snapshot.
You can easily find the delta of different snapshots by using Schema Compare. In this case, you can find out how your project evolves during the development process.