SQL Data Compare - 8.0
Learning SQL Data Compare - 8.0
Mapping objects
When you have selected your data sources, SQL Data Compare automatically maps tables and views with the same name and schema (owner).
However, if there are schema differences between the data sources, for example if two tables have different names, they may not be mapped automatically.
This topic provides information on
To compare tables and views that are not automatically mapped, click the Object Mapping tab of the Project Configuration dialog box :
The upper pane displays tables and views that are fully Mapped or have Partial mapping. The lower pane displays Unmapped tables and views.
Note that:
- Views are listed only if the data source is a database and the project option Include views is selected.
- If an object has a Partial mapping, some of its columns are not be mapped, and cannot be compared.
To set the column mappings for an object, click the Status box for the object you want to re-map.
- If the differences between objects are not significant, they are more likely to be automatically mapped if you select the options Ignore case of object names, Ignore spaces in object names, and Ignore underscores in object names
- If you are editing an existing project and the structure of the database has changed since you last ran the project, a warning symbol
is shown to indicate that those changes affect your project configuration.
Mapping tables and views
To map tables and views:
- On the Object Mapping tab, select an Unmapped table or view that you want to map from the source database.
- Select the Unmapped table or view that you want to map from the target database.
- Click
Map.SQL Data Compare moves the tables or views to the upper pane.
Note that if the tables and views that you are mapping contain columns with incompatible data types, SQL Data Compare cannot compare those columns; the column mapping shows the incompatible data types as Uncomparable and a warning symbol
is shown in the Tables & Views tab.
For more information, see Which data types can be compared?
To unmap tables and views:
- On the Object mapping tab, select a Mapped table or view, or a Partial mapping.
- Click
Unmap.
SQL Data Compare moves the tables or views to the lower pane.
Mapping specific columns
If you want to compare columns in a table or view and the column names are different, you can map the columns as required.
To map columns:
- On the Object mapping tab, click the Status box of a Partial mapping.
A dialog box is displayed. For example:

- Select an Unmapped column that you want to map from the source database.
- Select an Unmapped column that you want to map from the target database.
- Click
Map.SQL Data Compare moves the columns to the upper pane of the dialog box.
- Click Close.
Note that if a column is shown as Uncomparable, SQL Data Compare cannot compare the data that is stored in the column.
For more information, see Which data types can be compared?
To unmap columns:
- On the Object mapping tab, click the Status box of a Mapped table or view, or a Partial mapping.
A dialog box is displayed for you to specify the column mappings, as shown above.
- Select a Mapped column.
- Click
Unmap.SQL Data Compare moves the columns to the lower pane of the dialog box.
- Click Close.
See also |
Was this article helpful?
SQL Data Compare
- Logging and log files
- Internal Connection Fatal Error in versions 4 and 5
- NULL textptr passed to UPDATETEXT function when running synchronization
- How much free hard disk space is required?
- Comparing the data of two tables in the same database
- Suggestions to combat comparison and synchronization performance issues
- SQL comparison and synchronization automation capabilities
- SqlNullValueException occurring in synchronization wizard
- SQL Data Compare command-line XML argument file examples
- Using Windows authentication logons between domains
- Using a filter on a column on related (joined) tables
- Determining minimum database permissions for SQL Data Compare
- Tables with compound keys may not be mapped automatically
- Best practices for synchronizing data
- Cleaning up a SQL script after SQL Compare or SQL Data Compare
- Troubleshooting System.OutOfMemoryException during comparison
- Exception thrown by db reader 1
- Reseed applying "incorrect" identity values
- Running migration scripts using SqlCmd.exe
- This SQL Server has been optimized for x concurrent queries.
- SQL Data Compare showing differences in 2 identical databases
- How to force SQL Compare and SQL Data Compare to use an Encrypted Connection
- Improving the performance of SQL Data Compare
- Logging and log files
- Case-sensitive comparisons
- Tables or views that could not be compared
all SQL products
- Compatibility of Red Gate tools in 64-bit environments
- Application has encountered an error and needs to close
- Error message after installing SQL Toolbelt - The description for Event ID ( 1 ) in Source ( nview_info ) cannot be found.
- Changing the temporary directory used by the installer
- Toolbelt Installer "hanging" while "scanning volumes"
- Login failing with "trusted SQL Server connection" error when using RunAs
all products
- Some Red Gate products identified as containing a trojan by Anti-Virus software
- Activation may fail with Unknown Error -1
- Product uses web help although a CHM file is available locally
- Argument exception resulting from missing environment variable
- Check for updates may fail when used through proxies
- 'Unidentified Publisher' error when repairing or uninstalling
- Licensing activates product as standard edition
- Moving Red Gate software products to another machine
- Red Gate tools log locations
- The application UI opening slowly when there is no internet access
SQL Data Compare
- Activating your products
- Activating your products
- Getting help offline
- Getting better performance out of SQL Data Compare
- Release notes - version 10.xx
- SQL Data Compare release notes - version 7.xx
- SQL Data Compare release notes - version 8xx
- SQL Data Compare release notes - version 9.xx
all SQL products
all products
- Red Gate product acknowledgements
- Activating your products
- Activating your products
- Red Gate bundle history
- Check for updates
- Troubleshooting Check for Updates errors
- Current versions
- Deactivating your products
- Installing Red Gate products from the .msi file
- Requesting additional activations
- Serial numbers for bundles
- Reactivating using a different serial number
- Extending your trial
- Finding your serial numbers
- Moving a serial number from one computer to another
- No response received for manual activation
- Licensing and activation resources
- Licensing and activation resources
- Troubleshooting licensing and activation errors
- Licensing and activation FAQs
- Red Gate tools log file locations
- Download old versions of products
- Download product prerequisites & utilities
- Support & upgrades
- Upgrading your software
- Upgrading FAQs


Using SQL Data Compare