Question

If I have a primary key in table A and in table B of the same database (table B has its own primary key) I create a relationship with the primary key in table A so that a column in table B is the foreign key, does it mean that the primary key data created in the primary key column of table A will also be added to table B by virtue of it being a foreign key column or do I have to code that relationship, and if so how do I go about that?

Answer 1

In response to your question:

…do I have to code that
relationship, and if so how do I go
about that?

You will need to define the relationships between the two tables. Example:

ALTER TABLE tableB
ADD CONSTRAINT FK_tableB_TableA FOREIGN KEY (tableAId)
    REFERENCES tableA (id) ;

When you insert a record into tableB you will still need to define tableAId is. SQL Server doesn’t magically know what this should be.

So hypothetically if tableA looked like this:

1 | Some text | 1/1/2020
2 | blah blah | 6/1/2021

To insert a record in tableB that referenced record 2 you would need to do this:

INSERT INTO TableB (2,'My important information')

This assumes tableB has the following structure:

TableB
---------
Id --identity column/pk
tableAId --fk
SomeTextColumn