How to resolve the failure of setting foreign key constraints in Navicat?

There could be various reasons for the failure to set foreign key constraints in Navicat, below are some possible solutions:

1. Ensure that the data type and length of the foreign key column set match those of the corresponding column in the referenced table.
2. Ensure that the foreign key columns and the corresponding columns in the referenced table do not contain any null values.
3. Ensure that both the foreign key columns and the corresponding columns in the referenced table have the appropriate indexes.
4. Ensure that the foreign key column set and the corresponding column in the reference table have the same character set.
5. Ensure that the reference column in the reference table already exists in the table and has a unique index.

If none of the above methods work to solve the issue, it is recommended to try rebuilding the table structure and ensure that when setting foreign key constraints, follow the steps mentioned above. If the problem persists, it may be necessary to further examine the database configuration or contact Navicat’s technical support team for assistance.