To enable foreign key constraints on a connection you created yourself with open,Įxecute the SQL command PRAGMA foreign_keys=on with it. Sqlite does not enable checking for foreign key constraintsīut Norm does so automatically for every connection that Norm creates. Please note that Sqlite enforces foreign key constraints only when you use getDb() Select queries will only return the id referenced and not the associated fields: var consumer = newConsumer()ĭb.select(consumer, "email = $1", = product = newProduct()ĭb.select(product, "id = $1", consumer.productId)Įcho() SELECT "Consumer".email, "Consumer".productId, "Consumer".id FROM "Consumer" WHERE email = $1 LIMIT 1 <- "Product".name, "Product".price, "Product".id FROM "Product" WHERE id = $1 LIMIT 1 <- Create an INSERT statement to insert a new product using an invalid supplier and/or category ID to verify that foreign key constraints are being enforced. SQLite users should be aware of some caveats when using bulk inserts. Only Values The first method is to specify only the value of data to be inserted without the column names. There are two ways of using the SQL INSERT INTO statement for inserting rows. Let badProductId = 133 var paul = newConsumer( badProductId)Įcho getCurrentExceptionMsg() INSERT INTO "Consumer" (email, productId) VALUES(?, ?) <- 133] When a model has a foreign key, you can directly assign a model instance to the. The INSERT INTO statement of SQL is used to insert a new row/record in a table. If an invalid ID is passed, Norm will raise a DbError exception: try: INSERT INTO "Consumer" (email, productId) VALUES(?, ?) <- 1] The tables used in databases can have relationships with. This allows for more flexibility at the cost of more manual queries: var cheese = Product(name: "Cheese", price: 13.30)Įcho() INSERT INTO "Product" (name, price) VALUES(?, ?) <- 13.3] Foreign keys in SQLite are the values in a table that indicate the primary key of another table. INSERT statements can now be done using only id. When using fk pragma, foreign key must be handled manually, so createTables needs to be called for both Models: let db = open( ":memory:", "", "", "")Įcho() CREATE TABLE IF NOT EXISTS "Product"(name TEXT NOT NULL, price FLOAT NOT NULL, id INTEGER NOT NULL PRIMARY KEY)ĬREATE TABLE IF NOT EXISTS "Consumer"(email TEXT NOT NULL, productId INTEGER NOT NULL, id INTEGER NOT NULL PRIMARY KEY, FOREIGN KEY (productId) REFERENCES "Product"(id)) Proc newConsumer(email = "", productId = 0'i64): Consumer =Ĭonsumer(email: email, productId: productId) ProductId : int64 proc newProduct(): Product = Price: float Consumer = ref object of Model Since version 3.6.19, SQLite has included the capability to enforce Foreign Key constraints but this functionality currently must be activated for each database. To work around that limitation, you can declare and handle foreign keys manually, with fk pragma: import norm/ However, it has a downside: to fill up an object from the DB, Norm always fetches all related objects along with the original one, potentially generating a heavy JOIN query. I just tested these SQLite foreign key examples on my system, using SQLite version 3.4.0, and they all work fine.Norm handles foreign keys automatically if you have a field of type Model. INSERT INTO customers VALUES (null, 'FOOBAR', '200 Foo Way', 'Louisville', 'KY', '40207') ON DUPLICATE KEY UPDATE is a MariaDB/MySQL extension to the INSERT statement that, if it finds a duplicate unique or primary key, will instead. It enforces referential integrity within SQLite database. INSERT INTO customers VALUES (null, 'ACME, INC.', '101 Main Street', 'Anchorage', 'AK', '99501') SQLite Foreign Key is used to specify that values in one table also appear in another table. INSERT INTO salespeople VALUES (null, 'Barney', 'Rubble', 10.0) INSERT INTO salespeople VALUES (null, 'Fred', 'Flinstone', 10.0) If you'd like to test this SQLite foreign key example in your own SQLite database, here's some sample data for each of these tables: Next, define a SQLite table that has two foreign keys, one that relates a new orders table back to the customers table, and a second foreign key that relates the orders table back to the salespeople table:įOREIGN KEY(customer_id) REFERENCES customers(id),įOREIGN KEY(salesperson_id) REFERENCES salespeople(id)Īs you can see, the SQLite foreign key syntax is very similar to other databases. sqlite - How to insert values to a table from 2 foreign keys - Database Administrators Stack Exchange How to insert values to a table from 2 foreign keys Ask Question Asked 4 years, 1 month ago Modified 4 years ago Viewed 5k times 2 Hey guys was wanting some help. To show how this works, first define two database tables that don’t have any foreign keys: Here’s a quick SQLite foreign key example. The SQLite database does support foreign keys, and its foreign key syntax is similar to other databases. SQLite foreign keys FAQ: Can you show me how to define foreign keys in a SQLite database table design?
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