Before data migration, Data Transmission Service (DTS) checks the integrity constraints in the source database to make sure that the integrity constraints still hold after the migration.

This item checks whether all the parent and child tables with foreign key dependencies with the selected objects are also included in the migration scope. If this precheck item fails, certain parent tables are not selected in the migration scope. You can choose one of the following methods to fix this issue:

Add parent tables to the migration scope

Follow these steps to include parent tables of the tables that fail the precheck.

  1. Find the migration task and click Edit Task.Modify task configurations
  2. Click Set Whitelist and Next in the lower-right corner of the page.
  3. Select parent tables of the tables that fail to pass the precheck and click > to move them to the Selected section.Add to the objects to be migrated
  4. Click Precheck.

Remove child tables from the migration scope

Follow these steps to remove tables that fail the precheck from the objects to be migrated.

  1. Find the migration task and click Edit Task.Modify task configurations
  2. Click Set Whitelist and Next in the lower-right corner of the page.
  3. Select tables that fail to pass the precheck and click < to remove them from the Selected section.Remove tables from the objects to be migrated
  4. Click Precheck.

Delete foreign key dependencies

Follow these steps to delete foreign key dependencies from the source tables that fail to pass the precheck.

  1. Log on to the source database.
  2. Delete foreign key dependencies from the tables that fail the precheck.
    Note If the source database is on a managed database service provided by Alibaba Cloud, you can also log on to the DMS console to perform this operation. For more information, see Manage foreign keys.
  3. Perform another precheck.