11/7/2023 0 Comments Ios6 sqlite foreign key tutorial![]() ![]() # The python module puts the last row id inserted into a variable on the cursorĬ.execute("""INSERT INTO dog VALUES(NULL, 'spot')""")Ĭ. # Create a connection and cursor to your databaseĬ.execute("""INSERT INTO child VALUES(NULL, 'bobby')""") The sqlite3 module in python provides a nice little shortcut which saves you from having to run the 'last_insert_rowid()' function explicitly. SELECT last_insert_rowid() - gives the id of spot, assume 4 for this exampleĪlthough your question did not mention python, there is a python tag on this question so I'll assume you want to know how to do this in python. SELECT last_insert_rowid() - gives the id of bobby, assume 2 for this example Here are some example SQL statements for insert: INSERT INTO child VALUES(NULL, 'bobby') 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. The SQLite FOREIGN KEY constraint is used to link two tables together.You need to know the identifiers of both the child and the dog in order to. ![]() Inserts into the child_dog table (known as the mapping table) must happen after inserts into the child and dog tables. This requires three tables: CREATE TABLE child (įOREIGN KEY(child_id) REFERENCES child(id),Īn insert into each of the three tables must be separate SQL statements, but can take place in the context of same transaction. In order to support a child having zero or more dogs and a dog belonging to zero or more children, your database table structure needs to support a Many-To-Many relationship. ![]()
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