One article has only one family.
So by placing sqlite a foreign key in one table we create a one to many relationship,if we place another foreign key one the other table,we create a one to one relationship,now how we can create a Many to Many relationship?
Create table IF NOT exists families ( id integer primary KEY, reference varchar(32) NOT null, foreign name text NOT null, create unite varchar We then create a table of articles.
Sqlite insert into Publisher Values(1 JBL sqlite insert into Publisher Values(2 Cyberwit sqlite insert into Publisher Values(3 Indian Experss sqlite insert into Publisher Values(4 Economics Times sqlite select * from Publisher; Pub_id Pub_name JBL 2 Cyberwit 3 create Indian Experss 4 Economics Times Here in above we inserted some records in Publisher table.A foreign key constraint specifies create that for create each record in a child table containing a foreign key that there must also be a unique record that matches the key in the referenced or parent table.An example of SQlite tables with One to One relationship.We can do that by using two foreign keys on both sides of the relationship.Create table IF NOT exists families ( id integer primary KEY, reference varchar(32) NOT null, name text NOT null, unite varchar, create table IF NOT exists articles ( id integer primary KEY, reference varchar(32) NOT null, name text NOT null, quantity real, unite varchar, purchased.Create table IF NOT exists articles ( id integer primary KEY, reference varchar(32) NOT null, name text NOT null, quantity real, unite varchar, purchased integer, reserved integer, sold integer, available manager integer, minimum integer, family_id integer, foreign KEY(family_id) references families(id) As you can see we create.References tells SQlite the table and column we are relating to so we actually relate to a specific column in a table not the table itself.Following is the example of creating Foreign Key Constraint on column.We have a table of articles and families,an article can belong to only one family.
We can create multiple foreign KEY Constraints on columns in table foreign but all those columns must point to taekwondo primary KEY Constraint in other tables.
You can use foreign keys in SQLite to create many types of relationships between tables such as : One To Many relationship, one To One relationship, many To Many relationship.
Example of SQLite Foreign Key Constraint.
Assuming that foreign key support has been enabled for the session.What if we want to have a image one to one relationship with the two tables.em.Sqlite insert into book Values(6 html 7 Error: foreign KEY constraint drivers failed Here at the time of inserting 6th row in Book table we will get foreign KEY constraint failed error because the value " 7 " in the reference column pub_id not exists in Publisher table.So we have placed the foreign key in articles table.So we first create the SQLite table for families.Now we will delete recently inserted record from Book table where Pub_id value as 7 using following statement.When ON update cascade is used, the foreign key field in the child table will be updated to match the record(s) in the parent table.Create table table1 (col1 integer primary KEY, manager col2 text NOT null create table table2 (col3 integer primary KEY, col4 book text NOT null, col1 integer NOT null, foreign KEY (col1) references table1 If you observe above syntax we created table1 with col1 column as, primary KEY and we created table2 with col1 column as, foreign KEY and this column reference, primary KEY of table1.Appending ON delete cascade and ON update cascade will cause the SQLite Database Engine to make the necessary changes to the child table automatically.# Go to the Tools drop down menu in the Menu bar and select *Open On-connect SQL Tab.To express this relationship we need to add a Foreign key to families inside the articles table.Ideally, any necessary Foreign Key constraint should have been included when macx a table was created.This way our Foreign Key Constraint will help us to main the relationship between multiple tables based on our requirements).
An example of SQLite table with Foreign key.
create table detail(fk_master references master(mid) ON delete cascade.