在数据库中搜索名称并删除条目
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我正在制作一个Java程序,可以在其中使用Java并使用SQL命令访问数据库来制作本地食谱。我试图通过在文本字段中输入名称来删除数据库条目,然后在数据库中删除具有相同名称的匹配条目。我遇到一个奇怪的错误,它说“ executeQuerey()”不能用作更新,但是我那里仍然有更新方法。如果有人能找到解决该问题所需的措施,我将非常感激。谢谢!
/** Creates new form deleteRecipe */
public deleteRecipe()
initComponents();
/** This method is called from within the constructor to
* initialize the form.
* WARNING: Do NOT modify this code. The content of this method is
* always regenerated by the Form Editor.
*/
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents()
txtName = new javax.swing.JTextField();
jLabel1 = new javax.swing.JLabel();
btnDelete = new javax.swing.JButton();
btnBack = new javax.swing.JButton();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
txtName.setFont(new java.awt.Font("Lucida Grande", 0, 18)); // NOI18N
txtName.addActionListener(new java.awt.event.ActionListener()
public void actionPerformed(java.awt.event.ActionEvent evt)
txtNameActionPerformed(evt);
);
jLabel1.setFont(new java.awt.Font("Lucida Grande", 1, 18)); // NOI18N
jLabel1.setText("What Recipe do you want to delete?");
btnDelete.setText("Delete!");
btnDelete.addActionListener(new java.awt.event.ActionListener()
public void actionPerformed(java.awt.event.ActionEvent evt)
btnDeleteActionPerformed(evt);
);
btnBack.setText("Back");
btnBack.addActionListener(new java.awt.event.ActionListener()
public void actionPerformed(java.awt.event.ActionEvent evt)
btnBackActionPerformed(evt);
);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(87, 87, 87)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addComponent(jLabel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(txtName)))
.addGroup(layout.createSequentialGroup()
.addGap(199, 199, 199)
.addComponent(btnDelete, javax.swing.GroupLayout.PREFERRED_SIZE, 101, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(btnBack)))
.addContainerGap(80, Short.MAX_VALUE))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addComponent(btnBack)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 69, Short.MAX_VALUE)
.addComponent(jLabel1)
.addGap(30, 30, 30)
.addComponent(txtName, javax.swing.GroupLayout.PREFERRED_SIZE, 47, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(38, 38, 38)
.addComponent(btnDelete, javax.swing.GroupLayout.PREFERRED_SIZE, 45, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(34, 34, 34))
);
pack();
// </editor-fold>
private void txtNameActionPerformed(java.awt.event.ActionEvent evt)
// TODO add your handling code here:
private void btnBackActionPerformed(java.awt.event.ActionEvent evt)
this.dispose();
CookbookApp ca = new CookbookApp();
ca.setVisible(true);
private void btnDeleteActionPerformed(java.awt.event.ActionEvent evt)
ArrayList<Cookbook > recipes = new ArrayList();
String name = txtName.getText();
try
String url = "jdbc:derby://localhost:1527/Cookbook";
Connection conn = DriverManager.getConnection(url);
String query = "INSERT into RECIPES(NAME, SUBCATAGORY, CATAGORY, INGREDIENTS, INSTRUCTIONS, MODIFICATIONS) values(?,?,?,?,?,?)";
PreparedStatement pst = conn.prepareStatement(query);
pst.setString(1, name);
ResultSet rs = pst.executeQuery();
Cookbook recipe;
while (rs.next())
recipe = new Cookbook(rs.getString("NAME"), rs.getString("SUBCATAGORY"),rs.getString("CATAGORY"), rs.getString("INGREDIENTS"), rs.getString("INSTRUCTIONS"),rs.getString("MODIFICATIONS"));
if (rs.getString(1).equalsIgnoreCase(name))
recipes.remove(recipe);
pst.executeUpdate();
catch (Exception e)
JOptionPane.showMessageDialog(null, e);
//
// public ArrayList<Cookbook> recipes()
// ArrayList<Cookbook > recipes = new ArrayList();
//
// try
// String url = "jdbc:derby://localhost:1527/Cookbook";
// Connection conn = DriverManager.getConnection(url);
// String query = "SELECT * FROM RECIPES";
// PreparedStatement pst = conn.prepareStatement(query);
// ResultSet rs = pst.executeQuery();
//
// Cookbook recipe;
//
// pst.setString(1, name);
//
//
// while (rs.next())
// recipe = new Cookbook(rs.getString("NAME"), rs.getString("SUBCATAGORY"),rs.getString("CATAGORY"), rs.getString("INGREDIENTS"), rs.getString("INSTRUCTIONS"),rs.getString("MODIFICATIONS"));
// if (rs.getString(1).equalsIgnoreCase(name))
// recipes.remove(recipe);
//
// catch (Exception e)
// JOptionPane.showMessageDialog(null, e);
//
// return recipes;
//
/**
* @param args the command line arguments
*/
public static void main(String args[])
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels())
if ("Nimbus".equals(info.getName()))
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
catch (ClassNotFoundException ex)
java.util.logging.Logger.getLogger(deleteRecipe.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
catch (InstantiationException ex)
java.util.logging.Logger.getLogger(deleteRecipe.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
catch (IllegalAccessException ex)
java.util.logging.Logger.getLogger(deleteRecipe.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
catch (javax.swing.UnsupportedLookAndFeelException ex)
java.util.logging.Logger.getLogger(deleteRecipe.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
//</editor-fold>
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable()
public void run()
new deleteRecipe().setVisible(true);
);
// Variables declaration - do not modify
private javax.swing.JButton btnBack;
private javax.swing.JButton btnDelete;
private javax.swing.JLabel jLabel1;
private javax.swing.JTextField txtName;
// End of variables declaration
答案
这里的问题是,您尝试使用executeQuery方法执行INSERT SQL语句。当您要更新数据库(创建,更新,删除)时,必须调用executeUpdate。
如果要从数据库读取,则可以使用executeQuery方法执行此操作。
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