title: org.hibernate.exception.SQLGrammarException when trying to save record
body: <p>I am new to the world of JPA and hibernate. I have an entity EMPLOYEE for which I am trying to save a simple empty record but I keep on getting the following exception:</p>
  <pre><code> org.springframework.dao.InvalidDataAccessResourceUsageException: could not extract ResultSet; SQL [n/a]; nested exception is org.hibernate.exception.SQLGrammarException: could not extract ResultSet] with root cause java.sql.SQLSyntaxErrorException: Unknown column 'employee0_.employee_id' in 'field list'
  </code></pre>
  <p>My entity class looks like this:</p>
  <pre><code>package com.workforcesoftware.groupmanagementservice.data.entities;
  
  import javax.persistence.*;
  import java.io.Serializable;
  import java.util.List;
  import java.util.Objects;
  
  @Entity
  @Table(name = &quot;employee&quot;)
  public class Employee implements Serializable {
    @Id
    @Column(name = &quot;employeeId&quot;)
    private String employeeId;
    @Column(name = &quot;displayEmployeeId&quot;)
    private String displayEmployeeId;
    @Column(name = &quot;accountId&quot;)
    private String accountId;
    @Column(name = &quot;userId&quot;)
    private String userId;
    private String firstName;
    private String lastName;
    private String displayName;
    private String birthDate;
    private String phoneNumber;
    private String originalHireDate;
    private String externalMatchId;
  
    @OneToMany(mappedBy = &quot;employee&quot;)
    private List&lt;EffectiveDatedEmployee&gt; effectiveDatedEmployees;
    @OneToMany(mappedBy = &quot;employee&quot;)
    private List&lt;Job&gt; jobs;
  
  
    public Employee(){ }
  
    public Employee(String employeeId, String displayEmployeeId, String accountId, String userId, String firstName,
                    String lastName, String displayName, String birthDate, String phoneNumber, String originalHireDate,
                    String externalMatchId, List&lt;EffectiveDatedEmployee&gt; effectiveDatedEmployees, List&lt;Job&gt; jobs) {
      this.employeeId = employeeId;
      this.displayEmployeeId = displayEmployeeId;
      this.accountId = accountId;
      this.userId = userId;
      this.firstName = firstName;
      this.lastName = lastName;
      this.displayName = displayName;
      this.birthDate = birthDate;
      this.phoneNumber = phoneNumber;
      this.originalHireDate = originalHireDate;
      this.externalMatchId = externalMatchId;
      this.effectiveDatedEmployees = effectiveDatedEmployees;
      this.jobs = jobs;
    }
  }
  
  </code></pre>
  <p>My repository interface looks like:</p>
  <pre><code>public interface EmployeeRepository extends JpaRepository&lt;Employee, String&gt; {
  }
  </code></pre>
  <p>Finally, my repository calling code looks like this:</p>
  <pre><code>    Employee employee = new Employee(&quot;1&quot;, &quot;&quot;, &quot;&quot;, &quot;&quot;, &quot;&quot;, &quot;&quot;, &quot;&quot;, &quot;&quot;, &quot;&quot;, &quot;&quot;, &quot;&quot;, null, null);
      employeeRepository.save(employee);
  </code></pre>