Question

How do I relate one column to another column in another table? Would I create a column with the same name in another table?

Answer 1

You need to establish a FOREIGN KEY relationship. I this example, Main_Table.id is referenced as a foreign key in Related.main_table_id

Main_Table:
----------
id INT NOT NULL AUTO_INCREMENT,
value1 VARCHAR(8),
value2 VARCHAR(8)

Related:
---------
id INT NOT NULL AUTO_INCREMENT,
-- The related column doesn't have to have the same name
-- This column references Main_Table
main_table_id INT NOT NULL
-- The FOREIGN KEY constraint enforces the relationship
FOREIGN KEY (main_table_id) REFERENCES Main_Table (id)

Additionally, you can enforce the key relationship through deletion and update. If the row in Main_Table is deleted or has its id changed, you can force the change to cascade through the related table:

FOREIGN KEY (main_table_id) REFERENCES Main_Table (id) ON DELETE CASCADE ON UPDATE CASCADE
-- Or NULL it rather than delete it
FOREIGN KEY (main_table_id) REFERENCES Main_Table (id) ON DELETE SET NULL ON UPDATE CASCADE

See the documentation for full details.