has not been solved yet. I found a similar problem on https://stackoverflow.com/que... on stackoverflow. I tried it myself and found that it could not filter the subresult set, but only parent. The filtered parent brought out all the sub-objects,

@Entity
public class Player {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer id;

    private String name;

    @OneToMany(mappedBy = "player")
    private List<PlayerItem> playerItems;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public List<PlayerItem> getPlayerItems() {
        return playerItems;
    }

    public void setPlayerItems(List<PlayerItem> playerItems) {
        this.playerItems = playerItems;
    }
}

@Entity
public class PlayerItem {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer id;

    private String name;

    private Boolean begin;

    @ManyToOne
    @JoinColumn(name = "play_id")
    @JsonIgnore
    private Player player;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Boolean getBegin() {
        return begin;
    }

    public void setBegin(Boolean begin) {
        this.begin = begin;
    }

    public Player getPlayer() {
        return player;
    }

    public void setPlayer(Player player) {
        this.player = player;
    }
}

public interface PlayerRepository extends JpaRepository<Player, Integer> {
    List<Player> findByPlayerItemsName(String name);
}

@RestController
public class TestQcController {
    @Resource
    PlayerRepository repository;

    @PostMapping("test")
    public Object testQc() {
        List<Player> players = repository.findByPlayerItemsName("dada");
        return players;
    }
}

JSON

[{
    "id": 1,
    "name": "haha",
    "playerItems": [{
        "id": 1,
        "name": "dada",
        "begin": false
    }, {
        "id": 2,
        "name": "wawa",
        "begin": true
    }]
}]

my query condition is that the child object name equal to = "dada", only restricts the parent object, but the child object list does not restrict according to this condition

what should I do if I want to restrict sub-objects?