Issue 747 primary key autoname

[elca-anh]

Resolves #747

Description

• Add the relation identifier (i.e. table name) to the auto generated name of constraints
• For foreign-key constraints, add either the statement of the list of columns including the parent column

Checklist

• I have run this code in development and it appears to resolve the stated issue
• This PR includes tests, or tests are not required/relevant for this PR
• I have updated the CHANGELOG.md and added information about my change to the "dbt-databricks next" section.

[benc-db]

Thanks for opening, will run the test suite to see where we stand.

[PtrckGdwn]

Hi, I am really keen to use the non-expression method for foreign keys. Unfortunately, when I try it, I get an error message like: "No parent table defined for foreign key: " followed by a trace.

I have configured the schema for the model like so:

  - name: example__child_table
    constraints:
      - type: primary_key
        name: pk_example__child_table
        columns: ["id"]
      - type: not_null
        columns: ["id", "name", "parent_id"]
      - type: foreign_key
        name: fk_example__child_table_1
        columns: ["parent_id"]
        parent: parent_table
        parent_columns: ["id"]
    columns:
      - name: id
      - name: name
      - name: parent_id

Any tips on how to get this working? I've had a look at the macro code, and it appears the constraint.get("parent") call is not returning anything, hence the error message, but I can't see anything obvious I am doing wrong.

Running with adaptor version 1.8.5