How to read model columns in sql

Help
,
1

The problem I’m having

I need to create a incremental model which queries itself. In this case I can utilize the is_incremental() to point to itself with {{ this }} if it the table is not created yet or for full-refresh.
Example:

, cteX as (
{% if is_incremental() %}
select
     *,
  from {{ this }} join ...
  where ...
{% else %}
with cte_table as (
  select
       cast(null as id) as int,
       cast(null as name) as string,
       ...
) select * from cte_table where false
{{ endif }}
),

Here I don’t want to hardcode all the columns but rather utilize the schema yml with model description on which the column and datatype are already mentioned. How can I do that?

What I’ve already tried

There is a utility available get_filtered_columns_in_relation which queries the table to fetch columns. But I want the columns to be fetched from yml description for that model. Because it will be the first run and the table won’t be available yet.

2

in dbt your should start with the query and then move to documentation, especially with AI that will take the types and write your documentation.

Note: @Nick Pinfold originally posted this reply in Slack. It might not have transferred perfectly.