Top "Foreign-keys" questions

Foreign keys are a data integrity feature of relational (and SQL) databases.

SQlite - Android - Foreign key syntax

I've been trying to get foreign keys working within my Android SQLite database. I have tried the following syntax but …

android sqlite foreign-keys
Foreign keys in mongo?

How do I design a scheme such this in MongoDB? I think there are no foreign keys!

sql mongodb foreign-keys nosql
Add Foreign Key relationship between two Databases

I have two tables in two different databases. In table1 (in database1) there is a column called column1 and it …

sql sql-server tsql foreign-keys
When/Why to use Cascading in SQL Server?

When setting up foreign keys in SQL Server, under what circumstances should you have it cascade on delete or update, …

sql-server database-design foreign-keys rdbms cascade
Syntax error: missing expression (ORA-00936)

I have 2 tables, Facilities and Services. CREATE TABLE Facilities ( facility_id NUMBER(2) NOT NULL, facility_name VARCHAR2(20) NOT NULL, CONSTRAINT …

sql oracle database-design foreign-keys ora-00936
Adding a column as a foreign key gives ERROR column referenced in foreign key constraint does not exist

I have the following set up, CREATE TABLE auth_user ( id int PRIMARY KEY ); CREATE TABLE links_chatpicmessage (); I'm trying …

database postgresql foreign-keys alter-table
Primary and Foreign Key at the same time

Would it be possible in SQL Server 2008 to have a table created with 2 columns that are at the same time …

sql-server foreign-keys primary-key
postgresql foreign key syntax

I have 2 tables as you will see in my posgresql code below. The first table students has 2 columns, one for …

sql postgresql foreign-keys relational-database foreign-key-relationship
Does Foreign Key improve query performance?

Suppose I have 2 tables, Products and ProductCategories. Both tables have relationship on CategoryId. And this is the query. SELECT p.…

sql sql-server performance indexing foreign-keys
How to disable Constraints for all the tables and enable it?

I have 60 tables. I want to drop 10 tables where these 10 tables are Constraints(PK,FK) to other 20 tables. While dropping …

sql-server sql-server-2008 foreign-keys constraints foreign-key-relationship