private QueryExecution getSingleQueryExecution(String query, List<CustomDataSource> type) { char seperator = dbSeparator(type.get(0).type); StringBuilder builder = new StringBuilder(); Statement statement = sqlParser.createStatement(query, new ParsingOptions()); try { new RakamSqlFormatter.Formatter(builder, qualifiedName -> { String schema = qualifiedName.getPrefix().get().toString(); CustomDataSource customDataSource1 = type.stream() .filter(e -> e.schemaName.equals(schema)).findAny() .orElseThrow(() -> new RakamException("Cross database operations are not supported.", BAD_REQUEST)); return SupportedCustomDatabase.getAdapter(customDataSource1.type).getTableMapper() .apply(customDataSource1.options, qualifiedName.getSuffix()); }, seperator) { }.process(statement, 1); } catch (UnsupportedOperationException e) { return null; } String sqlQuery = builder.toString(); return new JDBCQueryExecution(() -> SupportedCustomDatabase.getAdapter(type.get(0).type).getDataSource().openConnection(type.get(0).options), sqlQuery, false, Optional.empty(), false); }