How to set primary key and foreign key in navicat

Navicat Set primary and foreign keys: Primary key: Select the column in the table that uniquely identifies each row, right-click and select "Set Primary Key". Foreign key: Select the column to create a foreign key, right-click and select "Modify Column", select the "Foreign Key" checkbox, and select the table and column associated with the foreign key. Details: Primary keys prevent data duplication and ensure data integrity. Foreign keys establish relationships between tables and ensure data consistency.

Navicat sets primary key and foreign key

Primary key

1. Click the table name to open the table design window.
2. Select the column to be set as the primary key.
3. Right-click on the selected column and select Set Primary Key.

Foreign Key

1. Click the table name where you want to create a foreign key to open the table design window.
2. Select the column to be set as a foreign key.
3. Right-click on the selected column and select Modify Column.
4. In the Column Information tab, select the Foreign Key checkbox.
5. In the Referenced table field, select the table associated with the foreign key.
6. In the Referenced column field, select the column associated with the foreign key.

Details

The primary key is a field that uniquely identifies each row in the table. It prevents data duplication and ensures data integrity. When setting up a primary key, you should choose a column with unique values, such as an ID number or unique identifier.

Foreign key is a column that points to a related record in another table. It is used to establish relationships between tables and ensure data consistency. When setting up a foreign key, you must select columns with unique key constraints to ensure that records can be linked correctly.

Tips

• The primary key can only be set to a single column.
• Allows a table to have multiple foreign keys.
• The foreign key must reference a column that exists in another table.
• If the referenced table or column is deleted, the foreign key will be automatically deleted in cascade.

The above is the detailed content of How to set primary key and foreign key in navicat. For more information, please follow other related articles on the PHP Chinese website!