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Does SQLite enforce foreign keys?
SQLite has supported foreign key constraint since version 3.6. If the SQLite library is compiled with foreign key constraint support, the application can use the PRAGMA foreign_keys command to enable or disable foreign key constraints at runtime.
How do foreign keys work SQLite?
A foreign key is a way to enforce referential integrity within your SQLite database. A foreign key means that values in one table must also appear in another table. The referenced table is called the parent table while the table with the foreign key is called the child table.
Can foreign key be null SQLite?
What is a Foreign Key with “Set Null on Delete” in SQLite? A foreign key with “set null on delete” means that if a record in the parent table is deleted, then the corresponding records in the child table will have the foreign key fields set to null. The records in the child table will not be deleted.
How to enable foreign key constraint in SQLite?
Note that Foreign keys constraints are not enabled by default in SQLite, you have to enable them first by the running the following command: PRAGMA foreign_keys = ON; Foreign key constraints were introduced in SQLite starting from version 3.6.
Is foreign key a constraint?
Primary keys and foreign keys are two types of constraints that can be used to enforce data integrity in SQL Server tables. These are important database objects.
How does the foreign key work in SQLite?
The SQLite foreign key is a basic that checks the presence of a huge worth present in one table to another table that has an association with the essential table where the foreign key is described. When we work with more than one table, when two tables define some relation between them that means one column is common from both tables.
Where does the child key go in SQLite?
Generally, the child key references to the primary key of the parent table. First, insert three rows into the supplier_groups table. Second, insert a new supplier into the suppliers table with the supplier group that exists in the supplier_groups table. This statement works perfectly fine.
What is a child table in SQLite called?
The suppliers table is known as a child table, which is the table to which the foreign key constraint applies. The group_id column in the supplier_groups table is called the parent key, which is a column or a set of columns in the parent table that the foreign key constraint references.
How does the Cascade action work in SQLite?
The CASCADE action propagates the changes from the parent table to the child table when you update or delete the parent key. Second, drop and create the table suppliers with the CASCADE action in the foreign key group_id :