Create a one to many relationship using SQL Server

1. Define two tables (example A and B), with their own primary key
2. Define a column in Table A as having a Foreign key relationship based on the primary key of Table B

This means that Table A can have one or more records relating to a single record in Table B.

If you already have the tables in place, use the ALTER TABLE statement to create the foreign key constraint:

ALTER TABLE A ADD CONSTRAINT fk_b FOREIGN KEY (b_id) references b(id) 

• fk_b: Name of the foreign key constraint, must be unique to the database
• b_id: Name of column in Table A you are creating the foreign key relationship on
• b: Name of table, in this case b
• id: Name of column in Table B