Fix DDL transaction handling for StarRocks

[inhouseaccman]

Fix DDL transaction handling to resolve error 5305

Problem

When running dbt unit tests, StarRocks throws error 5305:

5305 (25P01): Getting analyzing error. Detail message: Explicit transaction only support begin/commit/rollback/insert/update/delete/set/select statements.

This occurs because StarRocks does not support DDL statements (CREATE, DROP, ALTER, TRUNCATE) within explicit transactions. The current implementation sends COMMIT after DDL execution, which triggers this error.

Root Cause

• add_commit_query() was not overridden, using parent class which sends COMMIT ✗

When DDL statements are executed, the COMMIT causes StarRocks to fail.

Solution

1. Add _is_ddl_statement() static method - Detects DDL statements using regex patterns:

   • CREATE TABLE/VIEW/DATABASE/SCHEMA/INDEX/MATERIALIZED VIEW
   • DROP TABLE/VIEW/DATABASE/SCHEMA/INDEX/MATERIALIZED VIEW
   • ALTER TABLE/VIEW/DATABASE/SCHEMA
   • TRUNCATE TABLE

2. Override add_commit_query() - Skip COMMIT for DDL context, send COMMIT for DML

Changes

File	Changes
dbt/adapters/starrocks/connections.py	Add _is_ddl_statement() and add_commit_query()
tests/unit/test_connections.py	Add unit tests for DDL/DML transaction handling

Behavior

Statement Type	BEGIN	COMMIT
DDL (CREATE, DROP, etc.)	✗ Empty	✗ Empty
DML (INSERT, UPDATE, etc.)	✗ Empty	✓ COMMIT

Testing

• Added 23 new unit tests
• All 28 unit tests pass

$ python -m pytest tests/unit -v
======================= 28 passed, 2 warnings =======================

Test Cases

• DDL detection (21 parameterized tests)
• DDL execution flow (no BEGIN/COMMIT)
• DML execution flow (with COMMIT)

Checklist

• Code follows project style
• Unit tests added
• All tests pass
• No breaking changes to DML behavior

[CLAassistant]

All committers have signed the CLA.

[jaogoy]

@inhouseaccman Is it complete to solve the problem?

[inhouseaccman]

@inhouseaccman Is it complete to solve the problem?

Yes.

[chris-celerdata]

I cannot reproduce the bug this PR is supposed to fix on the current version. These lines were added in v1.10.

def add_begin_query(self):
        return self.add_query("", auto_begin=False)

Can you try updating to v1.10 to confirm whether these changes are needed?