Question

I have a table with a varchar datatype as the primary key. I’m trying to make a relationship to the junction table of this many-to-many relationship. I keep getting the error

The ALTER TABLE statement conflicted with the foreign key constraint
relationship name.

I don’t know what the deal is here. Since I have designated the field as a primary key and it was accepted, this means there are no dupes. Both the foreign key and the primary key are of the same datatype, with the same length. Neither one allows nulls. What else could the problem be?

Answer 1

Most likely, you have a value in your junction table that does not exist in the primary table, which prevents you from creating the foreign key relationship.

Try to find it with something like:

SELECT j.ICD_FK
    FROM ICD_Junction j
        LEFT JOIN ICD_text t
            ON j.ICD_FK = t.ICD_ID
    WHERE t.ICD_ID IS NULL;