How do I create a foreign key in SQL Server? - Stack Overflow
I have never "hand-coded" object creation code for SQL Server and foreign key decleration is seemingly different between SQL Server and Postgres. Here is my sql so far: drop table …
Cannot truncate table because it is being referenced by a …
Oct 31, 2008 · Because TRUNCATE TABLE is a DDL command, it cannot check to see whether the records in the table are being referenced by a record in the child table. This is why …
sql - Foreign Keys - What do they do for me? - Stack Overflow
Apr 21, 2013 · Foreign keys provide referential integrity. The data in a foreign key column is validated - the value can only be one that already exists in the table & column defined in the …
INSERT statement conflicted with the FOREIGN KEY constraint
56 You are trying to insert a record with a value in the foreign key column that doesn't exist in the foreign table. For example: If you have Books and Authors tables where Books has a foreign …
sql - What is difference between foreign key and reference key?
Dec 22, 2011 · A foreign key value in one row is said to "reference" the row that contains the corresponding key value. Note the word "reference" in the prior sentence is a verb, so we may …
sql - Can a foreign key be NULL and/or duplicate? - Stack Overflow
Mar 11, 2017 · By default there are no constraints on the foreign key, foreign key can be null and duplicate. while creating a table / altering the table, if you add any constrain of uniqueness or …
How can I list all foreign keys referencing a given table in SQL …
Jan 27, 2009 · I need to remove a highly referenced table in a SQL Server database. How can I get a list of all the foreign key constraints I will need to remove in order to drop the table? (SQL …
SQL - Unique Key, Primary Key & Foreign Key - Stack Overflow
Apr 25, 2015 · What are the differences between Unique Key, Primary Key and Foreign Key with respect to concept of SQL? How they are different from each other?
How can I find out what FOREIGN KEY constraint references a …
Jul 6, 2013 · Could not drop object 'dbo.UserProfile' because it is referenced by a FOREIGN KEY constraint. Msg 2714, Level 16, State 6, Line 2 There is already an object named 'UserProfile' …
sql server - Temporarily disable all foreign key constraints - Stack ...
Jul 25, 2012 · This is simple to do if your foreign key constraints are all simple, single-column constraints, but definitely more complex if there are multiple columns involved.