Miscellany

$schools = $conn->query('select s.name, variableCourse.name, fixedCourse.name, accommodation.name, transfer.name, transferPrice.one_way_price from School s LEFT JOIN
                              s.SchoolVariableDatesCourse variableCourse LEFT JOIN
                              s.SchoolFixedDatesCourse fixedCourse LEFT JOIN
                              s.SchoolAccommodation accommodation LEFT JOIN
                              s.SchoolTransfer transfer LEFT JOIN
                              transfer.SchoolTransferPrice transferPrice
                         where s.history_end_date IS NULL 
                               and variableCourse.history_end_date IS NULL 
                               and fixedCourse.history_end_date IS NULL 
                               and accommodation.history_end_date IS NULL 
                               and transfer.history_end_date IS NULL 
                               and transferPrice.history_end_date IS NULL 
                               and s.deleted = 0 
                               and variableCourse.deleted = 0 
                               and fixedCourse.deleted = 0
                               and accommodation.deleted = 0
                               and transfer.deleted = 0
                               and transferPrice.deleted = 0');