Foreign key relationships specify how tables relate to each other and indicate relationships between tables. PyCharm recognizes foreign key relationships in your database schema and uses them to construct JOIN clauses. You can see these relationships in the auto-completion list, data navigation, and diagrams. In PyCharm, you can use explicit foreign keys or create
virtual foreign keys. Foreign keys can be seen in the Database tool window. You can see a reference on node and object icons in the Icons for data sources and their elements chapter of
Database tool window topic. For the table column icons, refer to Possible icon combinations for columns. A foreign key is a field or a collection of fields in one table that
refers to the primary key in another table. When you create or modify a table, you can clearly define those keys: CREATE TABLE visitor ( id int NOT NULL, activity_id int NOT NULL, PRIMARY KEY (id), FOREIGN KEY (activity_id) REFERENCES activity(activity_id) ); The table that contains a foreign key is a child table. The table that contains a candidate key is a referenced or target table. If your database contains explicit foreign key relationships, PyCharm automatically uses them in auto-completion, data navigation, and diagrams. In the following example, Create a foreign key in a database
Productivity tipsModify templates for generated index and key namesWhen you create indexes, and primary and foreign key constraints, their default names are generated according to corresponding templates. For a primary key, for example, the template is
Last modified: 28 December 2022 Is the field in one table that refers to the primary key in another table?You can include the primary key fields in other tables to refer back to the table that is the source of the primary key. In those other tables, the fields are called foreign keys.
Which refers to a field or fields in a related table that identifies the primary key in a primary table?Primary Key - a field containing a value that uniquely identifies each record in a table. The primary key is unique and prevents entering duplicate records or a null value in that field. Foreign Key - a key in a related table that refers to the primary key in another table.
Which key refers to the field in a table that acts as the primary key?A foreign key is a column or group of columns in a relational database table that provides a link between data in two tables. It uniquely identifies a record in the relational database table. It refers to the field in a table which is the primary key of another table.
Which key is a field in one table whose values must match with the primary key values in related table?A foreign key is a column or a set of columns in a table whose values correspond to the values of the primary key in another table. In order to add a row with a given foreign key value, there must exist a row in the related table with the same primary key value.
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