我的oracle数据库表存在基本问题,而我使用JPA。
我的问题是,我通过添加ID列在数据库中创建表。当我回到我的JPA项目时,当我尝试创建新条目时,它不会为新项目创建ID。它总是说:尝试回滚事务时发生错误。
我搜索了这个问题。它基本上不会自动生成ID值。这是我的JPA控制器类:
@Entity
@Table(name = "PROJECTS", catalog = "", schema = "PROJETAKIP")
@XmlRootElement
@NamedQueries({
@NamedQuery(name = "Projects.findAll", query = "SELECT p FROM Projects p"),
@NamedQuery(name = "Projects.findById", query = "SELECT p FROM Projects p WHERE p.id = :id"),
@NamedQuery(name = "Projects.findByProject", query = "SELECT p FROM Projects p WHERE p.project = :project")})
public class Projects implements Serializable {
private static final long serialVersionUID = 1L;
// @Max(value=?) @Min(value=?)//if you know range of your decimal fields consider using these annotations to enforce field validation
@Id
@Basic(optional = false)
@Column(name = "ID", nullable = false, precision = 0, scale = -127)
@GeneratedValue(strategy= GenerationType.SEQUENCE)
private BigDecimal id;
@Column(name = "PROJECT", length = 255)
private String project;
public Projects() {
}
public Projects(BigDecimal id) {
this.id = id;
}
public BigDecimal getId() {
return id;
}
public void setId(BigDecimal id) {
this.id = id;
}
public String getProject() {
return project;
}
public void setProject(String project) {
this.project = project;
}
@Override
public int hashCode() {
int hash = 0;
hash += (id != null ? id.hashCode() : 0);
return hash;
}
@Override
public boolean equals(Object object) {
// TODO: Warning - this method won't work in the case the id fields are not set
if (!(object instanceof Projects)) {
return false;
}
Projects other = (Projects) object;
if ((this.id == null && other.id != null) || (this.id != null && !this.id.equals(other.id))) {
return false;
}
return true;
}
@Override
public String toString() {
return "com.ibb.souce.Projects[ id=" + id + " ]";
}
}
这是我的JSFClass:
@ManagedBean(name = "projectsController")
@SessionScoped
public class ProjectsController implements Serializable {
@Resource
private UserTransaction utx = null;
@PersistenceUnit(unitName = "DenemelerPU")
private EntityManagerFactory emf = null;
private Projects current;
private DataModel items = null;
private ProjectsJpaController jpaController = null;
private PaginationHelper pagination;
private int selectedItemIndex;
public ProjectsController() {
}
public Projects getSelected() {
if (current == null) {
current = new Projects();
selectedItemIndex = -1;
}
return current;
}
private ProjectsJpaController getJpaController() {
if (jpaController == null) {
jpaController = new ProjectsJpaController(utx, emf);
}
return jpaController;
}
public PaginationHelper getPagination() {
if (pagination == null) {
pagination = new PaginationHelper(10) {
@Override
public int getItemsCount() {
return getJpaController().getProjectsCount();
}
@Override
public DataModel createPageDataModel() {
return new ListDataModel(getJpaController().findProjectsEntities(getPageSize(), getPageFirstItem()));
}
};
}
return pagination;
}
public String prepareList() {
recreateModel();
return "List";
}
public String prepareView() {
current = (Projects) getItems().getRowData();
selectedItemIndex = pagination.getPageFirstItem() + getItems().getRowIndex();
return "View";
}
public String prepareCreate() {
current = new Projects();
selectedItemIndex = -1;
return "Create";
}
public String create() {
try {
getJpaController().create(current);
JsfUtil.addSuccessMessage(ResourceBundle.getBundle("/Bundle").getString("ProjectsCreated"));
return prepareCreate();
} catch (Exception e) {
JsfUtil.addErrorMessage(e, ResourceBundle.getBundle("/Bundle").getString("PersistenceErrorOccured"));
return null;
}
}
public String prepareEdit() {
current = (Projects) getItems().getRowData();
selectedItemIndex = pagination.getPageFirstItem() + getItems().getRowIndex();
return "Edit";
}
public String update() {
try {
getJpaController().edit(current);
JsfUtil.addSuccessMessage(ResourceBundle.getBundle("/Bundle").getString("ProjectsUpdated"));
return "View";
} catch (Exception e) {
JsfUtil.addErrorMessage(e, ResourceBundle.getBundle("/Bundle").getString("PersistenceErrorOccured"));
return null;
}
}
public String destroy() {
current = (Projects) getItems().getRowData();
selectedItemIndex = pagination.getPageFirstItem() + getItems().getRowIndex();
performDestroy();
recreatePagination();
recreateModel();
return "List";
}
public String destroyAndView() {
performDestroy();
recreateModel();
updateCurrentItem();
if (selectedItemIndex >= 0) {
return "View";
} else {
// all items were removed - go back to list
recreateModel();
return "List";
}
}
private void performDestroy() {
try {
getJpaController().destroy(current.getId());
JsfUtil.addSuccessMessage(ResourceBundle.getBundle("/Bundle").getString("ProjectsDeleted"));
} catch (Exception e) {
JsfUtil.addErrorMessage(e, ResourceBundle.getBundle("/Bundle").getString("PersistenceErrorOccured"));
}
}
private void updateCurrentItem() {
int count = getJpaController().getProjectsCount();
if (selectedItemIndex >= count) {
// selected index cannot be bigger than number of items:
selectedItemIndex = count - 1;
// go to previous page if last page disappeared:
if (pagination.getPageFirstItem() >= count) {
pagination.previousPage();
}
}
if (selectedItemIndex >= 0) {
current = getJpaController().findProjectsEntities(1, selectedItemIndex).get(0);
}
}
public DataModel getItems() {
if (items == null) {
items = getPagination().createPageDataModel();
}
return items;
}
private void recreateModel() {
items = null;
}
private void recreatePagination() {
pagination = null;
}
public String next() {
getPagination().nextPage();
recreateModel();
return "List";
}
public String previous() {
getPagination().previousPage();
recreateModel();
return "List";
}
public SelectItem[] getItemsAvailableSelectMany() {
return JsfUtil.getSelectItems(getJpaController().findProjectsEntities(), false);
}
public SelectItem[] getItemsAvailableSelectOne() {
return JsfUtil.getSelectItems(getJpaController().findProjectsEntities(), true);
}
@FacesConverter(forClass = Projects.class)
public static class ProjectsControllerConverter implements Converter {
public Object getAsObject(FacesContext facesContext, UIComponent component, String value) {
if (value == null || value.length() == 0) {
return null;
}
ProjectsController controller = (ProjectsController) facesContext.getApplication().getELResolver().
getValue(facesContext.getELContext(), null, "projectsController");
return controller.getJpaController().findProjects(getKey(value));
}
java.math.BigDecimal getKey(String value) {
java.math.BigDecimal key;
key = new java.math.BigDecimal(value);
return key;
}
String getStringKey(java.math.BigDecimal value) {
StringBuffer sb = new StringBuffer();
sb.append(value);
return sb.toString();
}
public String getAsString(FacesContext facesContext, UIComponent component, Object object) {
if (object == null) {
return null;
}
if (object instanceof Projects) {
Projects o = (Projects) object;
return getStringKey(o.getId());
} else {
throw new IllegalArgumentException("object " + object + " is of type " + object.getClass().getName() + "; expected type: " + Projects.class.getName());
}
}
}
}
当我手动分配ID时,它可以完美地工作。但我想要的是,它必须自动生成值。如何克服这个?
我的触发器:DELIMITER @@
CREATE OR REPLACE TRIGGER PROJETAKIP.PROJECTS_TRIGGER BEFORE INSERT ON PROJECTS REFERENCING NEW AS NEW FOR EACH ROW BEGIN SELECT PROJECTS_SEQUENCE.nextval INTO :NEW.ID FROM dual;END; @@
DELIMITER ;
答案 0 :(得分:0)
这是你应该如何使用序列生成器:
@GeneratedValue(strategy= GenerationType.SEQUENCE, generator="seq")
在课堂上:(例如,在@Entity
之后)
@SequenceGenerator(name="seq", sequenceName="PROJECTS_SEQUENCE", initialValue=1)
这应该适合你。
答案 1 :(得分:0)
保存对象时我遇到了同样的错误。 我的理由是因为将id范围的3位数添加到id值。 默认情况下,自动生成的ID将从1,2,3开始...... 我做了:
set
所以 - 在你的情况下 - 小心你的id注释 - 尝试启动没有scale,min和max值 - 看结果。例如,尝试:
as