CODEWITHSUNDEEP
javamysqljpajdbc
Pablo Gonzalez
Pablo Gonzalez

Reputation: 1810

@NamedQuery changes table/column name to upper case causing exepction

I have a table in MySql called Course and I have the following in my Course.java class

package pckt.book.ch7.jpa;

import java.io.Serializable;
import javax.persistence.*;


/**
 * The persistent class for the Course database table.
 * 
 */
@Entity
@NamedQuery(name="Course.findAll", query="SELECT c FROM Course c")
public class Course implements Serializable {
    private static final long serialVersionUID = 1L;

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

    private int credits;

    private String name;

    @Column(name="Teacher_id")
    private int teacher_id;

    public Course() {
    }

    public int getId() {
        return this.id;
    }

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

    public int getCredits() {
        return this.credits;
    }

    public void setCredits(int credits) {
        this.credits = credits;
    }

    public String getName() {
        return this.name;
    }

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

    public int getTeacher_id() {
        return this.teacher_id;
    }

    public void setTeacher_id(int teacher_id) {
        this.teacher_id = teacher_id;
    }

}

I'm the running the query as follows in another class

@PersistenceContext
EntityManager entityManager;

public List<Course> getCourseEntities(){
    //Use named query created in Course entitiy
    //using @NamedQuery annotation
    TypedQuery<Course> courseQuery = entityManager.createNamedQuery("Course.findAll",Course.class);
    return courseQuery.getResultList();
}

and I get the following error:

javax.persistence.PersistenceException: Exception [EclipseLink-4002]     (Eclipse Persistence Services - 2.5.2.v20140319-9ad6abd):     org.eclipse.persistence.exceptions.DatabaseException
Internal Exception: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Table   'course_management.COURSE' doesn't exist
Error Code: 1146
Call: SELECT ID, CREDITS, NAME, Teacher_id FROM COURSE
Query: ReadAllQuery(name="Course.findAll" referenceClass=Course sql="SELECT ID, CREDITS, NAME, Teacher_id FROM COURSE")

From reading the error, it sounds the issue is that the query generated by @NamedQuery is in upper case, therefore the COURSE table is not found.

In my.cnf I have lower_case_table_names=2 but not sure if that should make a difference.

My persistance.xml is as follows

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.1" xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">
    <persistence-unit name="CourseManagementEJB">
        <jta-data-source>jdbc/CourseManagement</jta-data-source>
        <class>pckt.book.ch7.jpa.Course</class>
    </persistence-unit>
</persistence>

jdbc/CourseManagement is a JNDI resource in GlassFish that points to a connection pool for the course_management database, where Course is a table. I know I can connect to the database successfully because I'm able to ping it.

Questions:

  1. Is it expected that queries are converted to upper case?
  2. How can I fix this issue?

I did do some research on this but wasn't able to find anything that fits my scenario. Some solutions recommended changing the table names (which I can't do) or changing the DAO classes names, which is not my case either.

Upvotes: 1

Views: 2582

Answers (2)

Lukas Eder
Lukas Eder

Reputation: 220877

Use backticks in the @Table annotation to make JPA use case sensitive names:

@Entity
@Table(name="`Course`")
@NamedQuery(name="Course.findAll", query="SELECT c FROM Course c")
public class Course implements Serializable { ...

Obviously, you have to use the real name as used in your database. E.g. if the name is all lower case, use:

@Table(name="`course`")

Upvotes: 5

Agbalaya Rasaq
Agbalaya Rasaq

Reputation: 125

Read through your exceptions it says :

 Internal Exception: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Table   'course_management.COURSE' doesn't exist

check through your persistence.xml file , the name you used to store the Database.

Make sure you don,t create your tables manually

Upvotes: 0

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