b.id as sub_id, b.teacher_borrow_id as sub_teacher_borrow_id, b.instrument_id as sub_instrument_id, b.instrument_name as sub_instrument_name, b.instrument_model as sub_instrument_model, b.instrument_num as sub_instrument_num, b.borrow_num as sub_borrow_num, b.damage_num as sub_damage_num, b.del_flag as sub_del_flag
from school_teacher_borrow a
left join school_teacher_borrow_detail b on b.teacher_borrow_id = a.id