Method _column_expr

xtop/core/query_builder.py:130–136

Return a projection expression respecting schema availability.

(self, source: str, alias: str, column: str, output_alias: str)

        return all(self._has_column(source, col) for col in columns)

    def _column_expr(self, source: str, alias: str, column: str, output_alias: str) -> str:
        """Return a projection expression respecting schema availability."""
        if self._has_column(source, column):
            actual = self._get_actual_column_name(source, column)
            column_ref = f"{alias}.{actual}"
            return f"{column_ref} AS {output_alias}"
        return f"NULL AS {output_alias}"
    
    def build_dynamic_query(self, 
                           group_cols: List[str],