JPA JPQL queries are transformed to uppercase

I am currently trying to set up my JPA backend for a job networking app. However, when I am trying to perform a JPQL query it always transforms it to upper case.

For example SELECT u.firstName FROM User will transform to SELECT FIRSTNAME FROM USER. This throws an exception since table USER does not exist.

If I create a table named USER in my mySql database then the problem is fixed but I would like to know why this is happening.

User entity:

@Entity
@NamedQuery(name="User.findAll", query="SELECT u.firstName FROM User u")
public class User implements Serializable {
    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    private int idUser;

    @Lob
    private String educationText;

    private String email;

    private String firstName;

    private int isModerator;

    @Lob
    private String jobExperienceText;

    private String lastName;

    private String password;

    private String phoneNumber;

    private String photoUrl;

    //bi-directional many-to-one association to Advertisment
    @OneToMany(mappedBy="user")
    private List<Advertisment> advertisments;

    //bi-directional many-to-one association to Article
    @OneToMany(mappedBy="user")
    private List<Article> articles;

    //bi-directional many-to-one association to Connection
    @OneToMany(mappedBy="user")
    private List<Connection> connections;

    //bi-directional many-to-one association to ConnectionRequest
    @OneToMany(mappedBy="user")
    private List<ConnectionRequest> connectionRequests;

    //bi-directional many-to-many association to Conversation
    @ManyToMany
    @JoinTable(
        name="ParticipantsOfConversation"
        , joinColumns={
            @JoinColumn(name="User_idUser")
            }
        , inverseJoinColumns={
            @JoinColumn(name="Conversation_idConversation")
            }
        )
    private List<Conversation> conversations;

    //bi-directional one-to-one association to User_has_Skill
    @OneToOne(mappedBy="user")
    private User_has_Skill userHasSkill;

    public User() {
    }

    public int getIdUser() {
        return this.idUser;
    }

    public void setIdUser(int idUser) {
        this.idUser = idUser;
    }

    public String getEducationText() {
        return this.educationText;
    }

    public void setEducationText(String educationText) {
        this.educationText = educationText;
    }

    public String getEmail() {
        return this.email;
    }

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

    public String getFirstName() {
        return this.firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public int getIsModerator() {
        return this.isModerator;
    }

    public void setIsModerator(int isModerator) {
        this.isModerator = isModerator;
    }

    public String getJobExperienceText() {
        return this.jobExperienceText;
    }

    public void setJobExperienceText(String jobExperienceText) {
        this.jobExperienceText = jobExperienceText;
    }

    public String getLastName() {
        return this.lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public String getPassword() {
        return this.password;
    }

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

    public String getPhoneNumber() {
        return this.phoneNumber;
    }

    public void setPhoneNumber(String phoneNumber) {
        this.phoneNumber = phoneNumber;
    }

    public String getPhotoUrl() {
        return this.photoUrl;
    }

    public void setPhotoUrl(String photoUrl) {
        this.photoUrl = photoUrl;
    }

    public List<Advertisment> getAdvertisments() {
        return this.advertisments;
    }

    public void setAdvertisments(List<Advertisment> advertisments) {
        this.advertisments = advertisments;
    }

    public Advertisment addAdvertisment(Advertisment advertisment) {
        getAdvertisments().add(advertisment);
        advertisment.setUser(this);

        return advertisment;
    }

    public Advertisment removeAdvertisment(Advertisment advertisment) {
        getAdvertisments().remove(advertisment);
        advertisment.setUser(null);

        return advertisment;
    }

    public List<Article> getArticles() {
        return this.articles;
    }

    public void setArticles(List<Article> articles) {
        this.articles = articles;
    }

    public Article addArticle(Article article) {
        getArticles().add(article);
        article.setUser(this);

        return article;
    }

    public Article removeArticle(Article article) {
        getArticles().remove(article);
        article.setUser(null);

        return article;
    }

    public List<Connection> getConnections() {
        return this.connections;
    }

    public void setConnections(List<Connection> connections) {
        this.connections = connections;
    }

    public Connection addConnection(Connection connection) {
        getConnections().add(connection);
        connection.setUser(this);

        return connection;
    }

    public Connection removeConnection(Connection connection) {
        getConnections().remove(connection);
        connection.setUser(null);

        return connection;
    }

    public List<ConnectionRequest> getConnectionRequests() {
        return this.connectionRequests;
    }

    public void setConnectionRequests(List<ConnectionRequest> connectionRequests) {
        this.connectionRequests = connectionRequests;
    }

    public ConnectionRequest addConnectionRequest(ConnectionRequest connectionRequest) {
        getConnectionRequests().add(connectionRequest);
        connectionRequest.setUser(this);

        return connectionRequest;
    }

    public ConnectionRequest removeConnectionRequest(ConnectionRequest connectionRequest) {
        getConnectionRequests().remove(connectionRequest);
        connectionRequest.setUser(null);

        return connectionRequest;
    }

    public List<Conversation> getConversations() {
        return this.conversations;
    }

    public void setConversations(List<Conversation> conversations) {
        this.conversations = conversations;
    }

    public User_has_Skill getUserHasSkill() {
        return this.userHasSkill;
    }

    public void setUserHasSkill(User_has_Skill userHasSkill) {
        this.userHasSkill = userHasSkill;
    }

}

Persistnce.xml

<?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="linkedInProject" transaction-type="RESOURCE_LOCAL">
        <class>model.Advertisment</class>
        <class>model.AdvertismentPK</class>
        <class>model.Advertisment_has_Skill</class>
        <class>model.Advertisment_has_SkillPK</class>
        <class>model.Application</class>
        <class>model.ApplicationPK</class>
        <class>model.Article</class>
        <class>model.ArticlePK</class>
        <class>model.Comment</class>
        <class>model.CommentPK</class>
        <class>model.Connection</class>
        <class>model.ConnectionPK</class>
        <class>model.ConnectionRequest</class>
        <class>model.ConnectionRequestPK</class>
        <class>model.Conversation</class>
        <class>model.Interest</class>
        <class>model.InterestPK</class>
        <class>model.Message</class>
        <class>model.MessagePK</class>
        <class>model.Skill</class>
        <class>model.User</class>
        <class>model.User_has_Skill</class>
        <properties>
            <property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/linkedIn"/>
            <property name="javax.persistence.jdbc.user" value="ld"/>
            <property name="javax.persistence.jdbc.password" value="---"/>
            <property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver"/>
        </properties>
    </persistence-unit>
</persistence>

The exception I receive:

Jul 26, 2018 1:01:49 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [servlets.UserServlet] in context with path [/linkedInProject] threw exception
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 'linkedIn.USER' doesn't exist
Error Code: 1146
Call: SELECT FIRSTNAME FROM USER
Query: ReportQuery(name="User.findAll" referenceClass=User sql="SELECT FIRSTNAME FROM USER")
    at org.eclipse.persistence.internal.jpa.QueryImpl.getDetailedException(QueryImpl.java:378)
    at org.eclipse.persistence.internal.jpa.QueryImpl.executeReadQuery(QueryImpl.java:260)
    at org.eclipse.persistence.internal.jpa.QueryImpl.getResultList(QueryImpl.java:469)
    at dao.UserDAOImpl.list(UserDAOImpl.java:27)
    at servlets.UserServlet.doGet(UserServlet.java:58)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:635)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at filters.EntityManagerInterceptor.doFilter(EntityManagerInterceptor.java:41)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:496)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:650)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:803)
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:790)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1459)
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Thread.java:748)

Solution

You can annotate your entity class with @Table and table name wrapped in backsticks to make it case-sensitive:

@Table(name="`User`")
@Entity
@NamedQuery(name="User.findAll", query="SELECT u.firstName FROM User u")