Set up Data Generator

This topic describes how to generate data using the built-in Data Generator tool.

Tip

Before generating data, back up the database you want to populate.

If you’re not satisfied with the results, you can adjust the settings and regenerate the data.

To set up Data Generator:

1. Open the Data Generator Project Properties dialog in one of these ways:

• In the top menu, select Database > Tasks > New Data Generation.
• In Database Explorer, right-click the server connection or database and select Tasks > New Data Generation.

2. On the Connection page, select the connection and database for data generation.

Note

To create a new connection, click Manage in the Connection dropdown list. In the Connection Manager dialog, click New to add a new connection. For more information, see Managing connections.

3. On the Options page, set up data generation options.

The table describes the data generation options.

Name	Group	Description	Default value
By specified number of	Row distribution mode	Sets the number of rows to populate.	1000 rows
By proportion of existing data in volume of	Row distribution mode	Specifies the percentage of rows to populate.	10%
By generation of data by time	Row distribution mode	Specifies the time period in seconds during which data will be generated for each table.	10 sec
Truncate data from table before generation	Row distribution mode	Determines if existing data in the target table should be removed before generating new test data. When selected, the table is truncated, and all existing rows are permanently deleted. When cleared, new data is appended to the existing table.
Random by timestamp	Value distribution mode	Populates every subsequent data generation with new random numbers.
Random by seed	Value distribution mode	Generates values based on a specified seed. Repopulating the column will generate the same set of values each time.	1
Sequential	Value distribution mode	Generates new random numbers for each subsequent data generation.
Set values to be unique	Column properties	Generates unique values.
Include NULL values % of rows	Column properties	Specifies the percentage of NULL values to generate.	10%
Include empty values % of rows	Column properties	Specifies the percentage of empty values to generate.	10%
Country-specific data	Column properties	Applies data conventions of a specific country to the generated data.	United States

4. Click Open to open a data generation project with the .dgen extension.

5. In the Tables and columns to populate pane, select the tables and columns for which you want to generate data.

6. Select the table and set up table generation settings. Repeat this step for each table you want to populate with data.

7. Select the column and set up column generation settings. Repeat this step for each selected column.

Note

All changes are displayed in the preview pane in real time.

Warning

Data generation may fail if a column includes a foreign key that references a table not included in the generation process.

To resolve the issue:

1. Select the table causing the error.

2. In the Table generation settings pane, navigate to the Related tables section.

3. Include or exclude the related parent and child tables as needed.

8. Click to open the Data Population Wizard.

9. On the Output page, select the output option to manage a data population script.

• Open the data population script in the internal editor.
• Save the script to a file. In this case, specify the path to the file.
• Execute the data population script against the database without reviewing it.

10. On the Options page, select general data population options.

Tip

You can click the name of an option to view its detailed description.

In the search box, you can start typing the option name. The options matching your search will be highlighted.

To save the options you’ve set for later use, click Save As My Defaults.

To use the default settings of the tool, click Devart Defaults.

To use the options you saved earlier, click My Defaults.

The table provides a list of data generation options available on the Options page.

Name	Group	Description	Default State
Use a single transaction	Transactions	Executes a data population script as a single transaction. All the changes to the databases will be rolled back if any error occurs during the script execution.	On
Disable check constraints	Common	Drops the CHECK and NOT NULL constraints at the beginning of the data population process. After data population, those constraints are restored by adding the WITH NOCHECK parameter. To restore the constraints with the WITH CHECK parameter, select Restore constraints using WITH CHECK.	Off
Disable DML triggers	Common	Disables DML triggers before data population. After data population, the triggers are enabled. The option is applicable to tables and views.	On
Disable foreign keys	Common	Drops foreign keys before data population. After data population, the foreign keys are restored.	On
Disable primary keys, indexes, and unique constraints	Common	Drops primary keys, indexes, and unique constraints before data population. After data population, they are restored. If a primary key, index, or unique constraint is used as a comparison key, it cannot be dropped.	Off
Disable rules	Common	Drops rules before data population. After data population, the rules are restored. This option is applied for the ON INSERT, ON UPDATE, and ON DELETE rules only.	Off
Exclude comments	Script Comments	Prevents comments generation in the data population script.	Off
Insert multiple rows of data	Common	Includes multiple rows of data in one INSERT clause.	On

11. On the Additional Scripts page, enter or select the script you want to execute before or after data population.

You might use this option in scenarios, such as dropping existing data or temporarily disabling triggers before data generation, then re-enabling them afterward.

12. On the Summary page, review the data generation action plan and check for any errors or warnings that highlight potential problems.

13. Click Generate to complete the data generation process.