fix: the database url is missing ":\\" when sqlite or postgresql is not used

[qq745639151]

If I set the environment varialbe LANGFLOW_DATABASE_URL start with "mysql+aiomysql://"， the function _create_engine split it to judge the database will be used. But if sqlite or postgresql is not used. the url is missing "://"

[codspeed-hq]

CodSpeed Performance Report

Merging #5492 will degrade performances by 23.93%

_{Comparing qq745639151:main (f9383d6) with main (870aedf)}

Summary

❌ 1 regressions
✅ 14 untouched benchmarks

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Benchmark	main	qq745639151:main	Change
❌	test_successful_run_with_input_type_any	274.4 ms	360.7 ms	-23.93%

Copilot reviewed 1 out of 1 changed files in this pull request and generated 1 comment.

The code should check if '://' is already present in the URL before appending it to avoid creating an invalid URL.

[ogabrielluiz]

Hey @qq745639151

Good catch. Please take a look at my comment.

[ogabrielluiz]

What about something like this:

    def _create_engine(self) -> AsyncEngine:
        """Create the engine for the database."""
        url_components = self.database_url.split("://", maxsplit=1)
        if url_components[0].startswith("sqlite"):
            scheme = "sqlite+aiosqlite"
            kwargs = {}
        else:
            kwargs = {
                "pool_size": self.settings_service.settings.pool_size,
                "max_overflow": self.settings_service.settings.max_overflow,
            }
            scheme = "postgresql+psycopg" if url_components[0].startswith("postgresql") else url_components[0]
        database_url = f"{scheme}://{url_components[1]}"
        return create_async_engine(
            database_url,
            connect_args=self._get_connect_args(),
            **kwargs,
        )