[CT-522] [Bug] query-comment should append comment for full-refresh and merge statements

[mkkuba]

Describe the bug

query-comment with append: true set does NOT append the query comment in Snowflake in the following cases:

• full refresh of a model
• merge statement on incremental updates

Steps To Reproduce

set query comment config to append: true

query-comment:
    append: true

Run a full refresh of a model
Observe in Snowflake query history that the query-comment is not appended in the query for the full-refresh

Run an incremental update of a model
Observe in Snowflake query history that the query-comment is not appended in the merge statement for the incremental update

Expected behavior

query-comment should be appended to the statements in the cases outlined above

Screenshots and log output

If applicable, add screenshots or log output to help explain your problem.

System information

The output of dbt --version:

installed version: 1.0.1
   latest version: 1.0.4

Your version of dbt is out of date! You can find instructions for upgrading here:
https://docs.getdbt.com/docs/installation

Plugins:
  - snowflake: 1.0.0

The operating system you're using:
MacOS Monterey 12.3.1

The output of python --version:
Python 3.9.9

Additional context

N/A

[jtcohen6]

@mkkuba Thanks for opening! You're totally right.

On Snowflake, we need to split up multi-query statements (containing ;), and pass each one as its own query. The issue here has been that query comments are applied before that split happens: the comment is applied in execute, the split occurs in add_query. I think the solution here should be relatively straightforward, possibly even related to the fix for #147.

[mkkuba]

Thanks @jtcohen6 !