[CT-78] [Bug] Adapters should be able to override string and numeric type of columns

[mdesmet]

Is there an existing issue for this?

• I have searched the existing issues

Current Behavior

String and numeric types are hardcoded in the base Column classes.

dbt-core/core/dbt/adapters/base/column.py

Lines 42 to 44 in a588607

	return Column.string_type(self.string_size())
	elif self.is_numeric():
	return Column.numeric_type(self.dtype, self.numeric_precision,

When running dbt_utils.union_relations with the Trino adapter, following columns are generated based, hoever varying is not supported by Trino and the Trino adapter suppleis an overriding method for string_type.

cast("administratieve groep/iov code" as character varying(256)) as "administratieve groep/iov code"

Expected Behavior

Adapters should be able to override the stirng and numeric types according to the specifications of the specific database.

Steps To Reproduce

No response

Relevant log output

No response

Environment

- OS: Macos
- Python: 3.9.10
- dbt: 1.0.0

What database are you using dbt with?

other (mention it in "Additional Context")

Additional Context

Trino

[McKnight-42]

@mdesmet Thank you for opening up this issue, been catching up on context and looking over your PRs going to go ahead and move this from triage to a good first issue and see if we can get the tests running on your PR.