java如何从父表中删除具有引用列的行到子表?
我在javaFx项目和SQlite数据库中使用JDBC。我有两个表"PROJECT"
和"SMAllPROJECT"
,比如PROJECT有这个结构PROJECT(name,date,state)
和SMAllPROJECT
有这个结构SMAllPROJECT(name,date,state,*project_name*)
Project_name
是从PROJECT table
的name
列引用的
我正在尝试从PROJECT
中删除行,SMAllPoject
中引用的行应该被删除。在sqlitestudio中,当我从父表中应用delete行时,我配置了onCascade
方法,当我在sqlitestudio中测试它时,一切都很好,但在我的代码中,它只是从父表中删除了行
这是我的代码:
控制器方法
public void ExecuteDeleteProject() {
if (!SearchIdProjectSupp.getText().isEmpty()) {
Project project = new ProjectDao().FindString(SearchIdProjectSupp.getText());
new ProjectDao().Delete(project);
String title = "Suppression";
String message = "Vous avez supprimé le projet " + SearchIdProjectSupp.getText() + ".";
NotificationType notification = NotificationType.SUCCESS;
TrayNotification tray = new TrayNotification();
tray.setTitle(title);
tray.setMessage(message);
tray.setNotificationType(notification);
tray.setAnimationType(AnimationType.SLIDE);
tray.setImage(new Image("Images/check.png"));
tray.setRectangleFill(Paint.valueOf("#a8a9fe"));
tray.showAndDismiss(Duration.seconds(4));
SearchIdProjectSupp.setText("");
SuppPaneProject.setVisible(false);
DeleteProjetButton.setDisable(true);
CountP.setVisible(true);
CountP();
CountR();
CountPP();
}
}
DAO模式方法
public boolean Delete(Project Object) {
try {
String queryDeletePerson = "DElETE FROM PROJECT WHERE name=" + "'" + Object.getName() + "'";//Query Insertion in Person_Table
PreparedStatement preparedStatementPerson = Dbaconnection.getConnection().prepareStatement(queryDeletePerson);//Prepared statement i use this for high performance
preparedStatementPerson.execute();
} catch (SQLException ex) {
Logger.getLogger(EMPDao.class.getName()).log(Level.SEVERE, null, ex);
}
return true;
}
这是我的DDL
CREATE TABLE PROJECT (
NAME VARCHAR2 (100) PRIMARY KEY,
STATE VARCHAR2 (100),
DATEDBT DATE,
);
CREATE TABLE SMALLPROJECT (
NAMEPROJECT VARCHAR2 (100) REFERENCES PROJECT (NAME) ON DELETE CASCADE
ON UPDATE CASCADE,
NAME VARCHAR2 (20) PRIMARY KEY,
DATEDBT DATE,
STATE VARCHAR2 (20) PRIMARY KEY
);
# 1 楼答案
根据SQLite Foreign Key Support和How do you enforce foreign key constraints in SQLite through Java? 的答案 ,它应该在执行任何查询之前配置数据库连接。我有这个问题,因为我没有强制外键约束