Erreur de syntaxe SQL rencontrée lors de la tentative de GET REQUEST

Question

Bonjour, j'essaie d'afficher les données de l'étudiant et son sujet correspondant en fonction de la clé étrangère subject_id et d'afficher le résultat sur GET REQUEST. Je ne sais pas comment réécrire la commande SQL pour éliminer l'erreur. L'erreur est la suivante :

java.sql.SQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'INNER JOIN subject ON student.subject_id=subject.id  WHERE user_id=3' at line 1Retrieve not successful

Voici mon schéma de base de données :

Voici mon code :

public ArrayList<Object> getStudentSubject(int id) throws Exception {
        Connection connection = null;

        ArrayList<Student> data = new ArrayList<>();
        ArrayList<Subject> data2=new ArrayList<>();
        ArrayList<Object> data3 = new ArrayList<>();

        try {
            connection = new MysqlDbConnectionService().getConnection();


            String select ="SELECT student.user_id, student.username, student.password, student.fullname,student.email, subject.id,subject.name" +
                    "FROM student INNER JOIN subject ON student.subject_id=subject.id  WHERE user_id=?";

            PreparedStatement ps = connection.prepareStatement(select);
            ps.setInt(1, id);
            ResultSet rs = ps.executeQuery();

            Student model = new Student();
            Subject model2 = new Subject();

            while (rs.next()) {

                model.setId(rs.getString("user_id"));
                model.setUsername(rs.getString("username"));
                model.setPassword(rs.getString("password"));
                model.setFullName(rs.getString("fullname"));
                model.setEmail(rs.getString("email"));

                model2.setId(rs.getInt("id"));
                model2.setName(rs.getString("username"));

                data.add(model);
                data2.add(model2);

                data3.add(data);
                data3.add(data2);
            }
        } catch (Exception e) {
            System.out.println(e + "Retrieve not successful");
        }

        return data3;


    }

Code maillot :

@Path("subject/{id}")
    @GET
    public Response getStudentwithSubject(@PathParam("id") int id) throws Exception {

        return Response.ok(new Gson().toJson(studentService.getStudentSubject(id))).build();
    }

Modèle étudiant :

package com.common.db.domain;


import com.google.gson.annotations.SerializedName;

public class Student {


    @SerializedName("id")
    private String id;

    @SerializedName("username")
    private String username;

    @SerializedName("password")
    private String password;

    @SerializedName("fullname")
    private String fullName;

    @SerializedName("email")
    private String email;



    public Student()
    {

    }


    public Student(String id, String username, String password, String fullName, String email)
    {
        super();
        this.id=id;
        this.username = username;
        this.password = password;
        this.fullName = fullName;
        this.email = email;
    }




    public String getId() {
        return id;
    }

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

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getFullName() {
        return fullName;
    }

    public void setFullName(String fullName) {
        this.fullName = fullName;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }
}

Modèle de thème :

package com.common.db.domain;
import com.google.gson.annotations.SerializedName;
public class Subject {




    @SerializedName("id")
    private int id;

    @SerializedName("name")
    private String name;


    public Subject() {
        this.id = id;
        this.name=name;
    }

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

    public int getId()
    {
        return id;
    }

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

    public String getName()
    {
        return name;
    }



}

Answer 1

Si vous n'observez aucun espace entre subject.name 和 FROM Student, alors c'est complètement faux SQL en raison de la concaténation de chaînes. Ajoutez un espace après subject.name ou avant FROM comme indiqué ci-dessous.

String select ="SELECT student.user_id, student.username, student.password, student.fullname,student.email, subject.id,subject.name " +
                    " FROM student INNER JOIN subject ON student.subject_id=subject.id  WHERE user_id=?";

S'il vous plaît dites-moi si cela aide.