英文:
How to implement JPQL query?
问题
我在PostgreSQL中有一个有效的查询：
select s.id, s.seat_number as available_seat, s.row_number as available_row, rm.room_name as screening_room
from seats s
join rooms rm on rm.id=s.room_id
left join (
select r.seat_id from reserved_seats r
join reservations res on res.id=r.reservation_id AND res.screening_id = 3 ) res on res.seat_id=s.id
where res.seat_id is null AND s.room_id=3
ORDER BY s.id;
但是我在将其翻译为JPA查询语言时犯了错误。
我可以在JPQL中使用嵌套SELECT吗？
答案是使用原生查询：
@Query(value =
"SELECT s.id seatId, s.seat_number availableSeat, " +
"s.row_number availableRow, rm.name screeningRoom \n" +
"FROM seats s\n" +
"JOIN rooms rm on rm.id=s.room_id\n" +
" LEFT JOIN (\n" +
" SELECT r.seat_id FROM reserved_seats r\n" +
" JOIN reservations res ON res.id=r.reservation_id " +
" AND res.screening_id = :screeningId) res ON res.seat_id=s.id\n" +
"WHERE res.seat_id IS NULL AND s.room_id=:roomId AND s.row_number=:rowNumber\n" +
"ORDER BY s.id;", nativeQuery = true)
英文:
I have working query in PostgreSQL:
select s.id, s.seat_number as available_seat, s.row_number as available_row, rm.room_name as screening_room
from seats s
join rooms rm on rm.id=s.room_id
left join (
select r.seat_id from reserved_seats r
join reservations res on res.id=r.reservation_id AND res.screening_id = 3 ) res on res.seat_id=s.id
where res.seat_id is null AND s.room_id=3
ORDER BY s.id;
But I make mistakes translating it into the JPA query language.
Can I use nested SELECTs in JPQL?
The answer is to use native query:
@Query(value =
"SELECT s.id seatId, s.seat_number availableSeat, " +
"s.row_number availableRow, rm.name screeningRoom \n" +
"FROM seats s\n" +
"JOIN rooms rm on rm.id=s.room_id\n" +
" LEFT JOIN (\n" +
" SELECT r.seat_id FROM reserved_seats r\n" +
" JOIN reservations res ON res.id=r.reservation_id " +
" AND res.screening_id = :screeningId) res ON res.seat_id=s.id\n" +
"WHERE res.seat_id IS NULL AND s.room_id=:roomId AND s.row_number=:rowNumber\n" +
"ORDER BY s.id;", nativeQuery = true)
答案1
得分: 0
@Query(value =
"SELECT s.id seatId, s.seat_number availableSeat, " +
"s.row_number availableRow, rm.name screeningRoom \n" +
"FROM seats s\n" +
"JOIN rooms rm on rm.id=s.room_id\n" +
" LEFT JOIN (\n" +
" SELECT r.seat_id FROM reserved_seats r\n" +
" JOIN reservations res ON res.id=r.reservation_id " +
" AND res.screening_id = :screeningId) res ON res.seat_id=s.id\n" +
"WHERE res.seat_id IS NULL AND s.room_id=:roomId AND s.row_number=:rowNumber\n" +
"ORDER BY s.id;", nativeQuery = true)
英文:
The answer is to use native query:
@Query(value =
"SELECT s.id seatId, s.seat_number availableSeat, " +
"s.row_number availableRow, rm.name screeningRoom \n" +
"FROM seats s\n" +
"JOIN rooms rm on rm.id=s.room_id\n" +
" LEFT JOIN (\n" +
" SELECT r.seat_id FROM reserved_seats r\n" +
" JOIN reservations res ON res.id=r.reservation_id " +
" AND res.screening_id = :screeningId) res ON res.seat_id=s.id\n" +
"WHERE res.seat_id IS NULL AND s.room_id=:roomId AND s.row_number=:rowNumber\n" +
"ORDER BY s.id;", nativeQuery = true)
通过集体智慧和协作来改善编程学习和解决问题的方式。致力于成为全球开发者共同参与的知识库，让每个人都能够通过互相帮助和分享经验来进步。
评论