You can use Visual Studio Team System Database Edition to create test data that you need to verify the behavior of the database objects in your database project. You can generate data that is appropriate for the schema of the database but unrelated to the production data. This approach can help you protect the privacy or security of the production data.
You define a data generation plan that specifies the details of how you want data to be generated for specific tables and columns. For each column, you specify a data generator that produces data of a particular type.
When you create a data generation plan in a database project, the plan is based on the schema of the project. If you create a data generation plan and then the schema changes, you are prompted to update the plan.
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If you do not update the data generation plan based on the schema changes, you cannot continue to modify the plan. You can only close and reopen the data generation plan to display the prompt again. |
When you run database unit tests, you can specify a different data generation plan for each test project. Therefore, you can initialize the database to a different state for each group of tests.
Database Edition includes several built-in data generators for generating different kinds of data. For example, the integer generator provides random integer values, the string generator provides random strings, and the regular expression generator provides strings that match a pattern that you specify. For more information and the complete list of standard data generators, see Standard Data Generator Types and Specify Details of Data Generation for a Column.
If the generators that are included with Database Edition do not provide data that meets your requirements, you can create custom generators. For example, you might want to create a custom data generator if your database contains a column that has a check constraint that references another column. For more information, see Generate Specialized Test Data with a Custom Data Generator.
Data Generation Plans in a Team Environment
A data generation plan is an XML file that contains information about the database schema and configuration information that controls the data generation for each column in each table that you specify. A data generation plan for a database that contains about 40 tables can be about 8 MB and more than 100,000 lines long.
You cannot automatically merge changes to a .dgen file by using Team Foundation version control or another version control system. The process that you must use to manually merge large XML files is difficult and prone to errors. You can minimize problems that relate to your data generation plan by using exclusive checkout on it when you must change it.
Security of Data Generators
You can share data generation plans and custom data generators in a team environment. Before you share or use shared data generation files, you should consider the following security risks:
- Schema Information in Data Generation Plans
When you create a data generation plan, the .dgen file contains the schema of the tables, which might be a sensitive trade secret. When you share a .dgen file, the person with whom you share the file can see your schema. You should share data generation plans only with trusted sources.
- Malicious Code in Data Generation Plans
When a data generation plan contains a data bound generator, you write a Transact-SQL (T-SQL) query that runs when the plan is run. This approach allows arbitrary T-SQL to run from within a data generation plan. You should obtain data generation plans only from trusted sources and warn end users not to run data generation plans that they receive from non-trusted sources.
- Connection Information and Custom Data Generators
All custom data generators have access to the database connection string at run-time. A malicious custom generator could expose the connection string information. You should obtain custom data generators only from trusted sources and warn end users not to use custom data generators that they receive from non-trusted sources.
- Malicious Code in Custom Data Generators
Custom data generators are classes that can contain arbitrary code. When you use a custom data generator, it runs with the same permissions as the active user. This approach can run malicious code in FullTrust mode. You should obtain custom data generators only from trusted sources and warn end users not to use custom data generators that they receive from non-trusted sources.
- Malicious Code in Installers for Custom Data Generators
You can create deployment projects to install custom data generators. Deployment projects can contain arbitrary code. When you run an installation program for a custom data generator, the program runs with elevated permissions. This approach can run malicious code with elevated permissions. You should obtain custom data generator installers only from trusted sources and warn end users not to run installation programs for custom data generators that they receive from non-trusted sources.
In the following table, you can find descriptions of common tasks that support this scenario and links to more information about how you can successfully complete those tasks.
- Create and Define Database Unit Tests
Provides information and links to additional topics about how you can define unit tests to verify the behavior of your database objects. You can associate each test project with a different data generation plan, deployment configuration, and connection string.
- Run Database Unit Tests
Describes how, after you create your database unit tests, you run them to see the results.
- Define Custom Conditions for Database Unit Tests
Describes how you can test for a special condition that you cannot verify by using the default test conditions.
Concepts