SQL 錯誤：違反完整性約束：外鍵沒有父級

Question

我正在努力找出我的查詢做錯了什么。 我沒有創建數據庫，但這是結構：

3張桌子：

車輛：品牌、電機、價格、名稱、ID

選項：ID、描述、價格

vehicule_option：id_vehicule，id_option

我猜 vehicule_option 有 2 個外鍵，但我找不到我添加的問題。 這是我的第一部分工作正常的代碼：

public boolean create(Vehicule v){
        String query = "INSERT INTO vehicule (MARQUE, MOTEUR, PRIX, NOM) VALUES (";
        query += v.getMarque().getId() + ", "
                + v.getMoteur().getId() + ", "
                + v.getPrix() + ", \'"
                + v.getNom() + "\');";

        for (Option o : v.getOptions()){
            query += "INSERT INTO vehicule_option (id_vehicule, id_option) VALUES ("
                    + v.getId() + ", " + o.getId() + ");";
        }


        try{
            Statement state = this.connect.createStatement();
            ResultSet rs = state.executeQuery(query);
        } catch (SQLException e){
            e.printStackTrace();
        }
        return true;
    }

所以，我在這里所做的基本上是將兩個值插入到正確的列中。 它給了我以下異常：

java.sql.SQLIntegrityConstraintViolationException: integrity constraint violation: foreign key no parent; SYS_FK_10132 table: VEHICULE_OPTION
    at org.hsqldb.jdbc.JDBCUtil.sqlException(Unknown Source)
    at org.hsqldb.jdbc.JDBCUtil.sqlException(Unknown Source)
    at org.hsqldb.jdbc.JDBCStatement.fetchResult(Unknown Source)
    at org.hsqldb.jdbc.JDBCStatement.executeQuery(Unknown Source)
    at fr.ocr.sql.DAOVehicule.create(DAOVehicule.java:35)
    at fr.ocr.ihm.AddCarDialogBox$1.actionPerformed(AddCarDialogBox.java:151)
    at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
    at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
    at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
    at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
    at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
    at java.awt.Component.processMouseEvent(Unknown Source)
    at javax.swing.JComponent.processMouseEvent(Unknown Source)
    at java.awt.Component.processEvent(Unknown Source)
    at java.awt.Container.processEvent(Unknown Source)
    at java.awt.Component.dispatchEventImpl(Unknown Source)
    at java.awt.Container.dispatchEventImpl(Unknown Source)
    at java.awt.Component.dispatchEvent(Unknown Source)
    at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
    at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
    at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
    at java.awt.Container.dispatchEventImpl(Unknown Source)
    at java.awt.Window.dispatchEventImpl(Unknown Source)
    at java.awt.Component.dispatchEvent(Unknown Source)
    at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
    at java.awt.EventQueue.access$500(Unknown Source)
    at java.awt.EventQueue$3.run(Unknown Source)
    at java.awt.EventQueue$3.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
    at java.awt.EventQueue$4.run(Unknown Source)
    at java.awt.EventQueue$4.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
    at java.awt.EventQueue.dispatchEvent(Unknown Source)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
    at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.run(Unknown Source)
Caused by: org.hsqldb.HsqlException: integrity constraint violation: foreign key no parent; SYS_FK_10132 table: VEHICULE_OPTION
    at org.hsqldb.error.Error.error(Unknown Source)
    at org.hsqldb.Constraint.getException(Unknown Source)
    at org.hsqldb.Constraint.checkInsert(Unknown Source)
    at org.hsqldb.StatementDML.performIntegrityChecks(Unknown Source)
    at org.hsqldb.StatementDML.insertSingleRow(Unknown Source)
    at org.hsqldb.StatementInsert.getResult(Unknown Source)
    at org.hsqldb.StatementDMQL.execute(Unknown Source)
    at org.hsqldb.Session.executeCompiledStatement(Unknown Source)
    at org.hsqldb.Session.executeDirectStatement(Unknown Source)
    at org.hsqldb.Session.execute(Unknown Source)
    ... 40 more

Answer 1

從您在此處顯示的內容來看，車輛選項似乎有兩個外鍵，分別是車輛表中的 id 和選項表中的 id。

當您插入時，車輛 id 不在車輛表中，或者選項 id 不在其選項表中。

Answer 2

您剛剛插入了一個新的vehicule記錄，那么您如何知道v.getId()中該記錄的 id 呢？

你沒有，而且v.getId()很可能是0 ，因為你正在創建一個新的。

Answer 3

如果您通過“o”變量進行迭代，您應該使用 o.getId() 而不是 v.getId()