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14 paź 2009 · This document describes the support for SQL foreign key constraints introduced in SQLite version 3.6.19 (2009-10-14). The first section introduces the concept of an SQL foreign key by example and defines the terminology used for the remainder of the document.
SQLite Foreign Key. Summary: in this tutorial, you will learn how to use the SQLite foreign key constraint to enforce the relationships between related tables. SQLite foreign key constraint support. SQLite has supported foreign key constraint since version 3.6.19.
foreign-key-clause. REFERENCES foreign-table (column-name), ON DELETE SET NULL UPDATE SET DEFAULT CASCADE RESTRICT NO ACTION MATCH name NOT DEFERRABLE INITIALLY DEFERRED INITIALLY IMMEDIATE. Used by: column-constraint table-constraint See also: lang_altertable.html lang_createtable.html.
18 gru 2012 · Because of the foreign key constraint, an insert into the child_dog table would fail if the child and/or dog referenced do not exist in the database or transaction. Here are some example SQL statements for insert:
28 sie 2023 · Let’s dive into how we can implement a foreign key in SQLite. To start, you’ll need to enable the foreign key constraint. By default, it’s turned off in SQLite. You can turn it on using PRAGMA foreign_keys = ON; command. Next comes the creation of tables that will use the foreign key.
Here is the syntax of SQLite FOREIGN KEY constraint: First, the parent table is created. CREATE TABLE parent_table ( column_name1 datatype PRIMARY KEY AUTOINCREMENT, column_name2 datatype NOT NULL, column_name3 datatype, ... ); Second, the child table is created, it will contain the foreign key to the parent table.
1 gru 2023 · A FOREIGN KEY is a field/column(or collection of fields) in a table that refers to a PRIMARY KEY in another table. It is used for linking one or more than one table together. FOREIGN KEY is also called referencing key. A Foreign key creates a link (relation) between two tables thus creating referential integrity. In this article, we will learn abou
