fix: use fully qualified name to resolve DuckDB ambiguous reference error

[jerome-ng]

Suggested fix for OHDSI/Data2Evidence#1914.

Unsure how to test it

https://duckdb.org/docs/stable/sql/statements/attach#resolving-conflicts

[Copilot]

Pull request overview

Fixes a DuckDB “Ambiguous reference to catalog or schema” error by changing how $$SCHEMA$$ placeholders are expanded in generated SQL within the TREX runtime.

Changes:

• Expand $$SCHEMA$$ replacements from schema.table to catalog.schema.table by prepending the current database/catalog name.
• Add inline documentation explaining the DuckDB ambiguity being addressed.

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[Copilot]

This change always rewrites $$SCHEMA$$.* references to a 3-part name (catalog.schema.table), but the comment/PR context suggests it’s only required when the catalog name and schema name collide (e.g., databaseCode === schemaName). To reduce the blast radius of SQL generation changes, consider only prefixing with ${databaseName}. when schemaName !== "" and schemaName === databaseName (or otherwise detecting the ambiguous case), and keep the prior ${schemaName}. behavior for the common case.

Suggested change

	// "Ambiguous reference to catalog or schema" error when databaseCode equals schemaName
	const databaseName = this.connection.getdatabase();
	const replacement = schemaName === "" ? "" : `${databaseName}.${schemaName}.`;
	// "Ambiguous reference to catalog or schema" error when databaseCode equals schemaName.
	// To reduce blast radius, only include the catalog when the schema name collides with it.
	const databaseName = this.connection.getdatabase();
	let replacement = "";
	if (schemaName !== "") {
	if (schemaName === databaseName) {
	replacement = `${databaseName}.${schemaName}.`;
	} else {
	replacement = `${schemaName}.`;
	}
	}