所以我对我的数据库有这个问题，我正在处理我的错误，我的程序使用java连接Mysql和Neatbeans的信息....问题是我什么时候
Introducing information in my program
如果您需要我的数据库和代码的信息，我将把它留在这里
package jproject;
/**
*
* @author KK
*/
public class JProject {
public static void main(String[] args) {
}
}
MYSQL上的数据库
package jproject;
import java.sql.*;
import javax.swing.DefaultListModel;
import javax.swing.JOptionPane;
/* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
/**
*
* @author KK
*/
public class JProject2 extends javax.swing.JFrame {
static Connection conn= null;/*metodos de tipo SQL para usar en la BD*/
static Statement st=null;
static ResultSet rs=null;
DefaultListModel mod1= new DefaultListModel();
DefaultListModel mod2= new DefaultListModel();
DefaultListModel mod3= new DefaultListModel();
DefaultListModel mod4= new DefaultListModel();
/*datos de la BD para la conexion*/
static String bd="colorines";
static String login="root";
static String pass="";
static String url="jdbc:mysql://localhost/"+bd;
/*Metodo para hacer la conexion a la bd*/
public static Connection Enlace(Connection conn)throws SQLException
{
try
{
Class.forName("com.mysql.jdbc.Driver");
conn= DriverManager.getConnection(url,login,pass);
}
catch(ClassNotFoundException c)
{
JOptionPane.showMessageDialog (null,c);
}
return conn;
}
/**
* Creates new form Conecta
*/
public JProject2() {
initComponents();
jTextField1.setText("");
jTextField2.setText("");
jTextField3.setText("");
jTextField4.setText("");
jTextField5.setText("");
jTextField6.setText("");
jList1.setModel(mod1);
jList2.setModel(mod2);
jList3.setModel(mod3);
jList4.setModel(mod4);
String cadena="";
try
{
conn=Enlace(conn); /*creo la conexion con la base de datos*/
st=conn.createStatement(); /*Especifico que hare una consulta sobre conn que contiene mi base de datos*/
rs=st.executeQuery("select * from informacion"); /*guardo en rs result set, mi consulta de toda la tabla "informacion"*/
while(rs.next()) /*mientras rs result set (contiene la tabla informacion), tenga datos para leer, sigue leyendo*/
{
/*cadena=cadena+rs.getString(1)+" - "+rs.getString(2)+" - "+rs.getString(3)+" - "+rs.getString(4)+"\n"; */
mod1.addElement(rs.getString(1));
mod2.addElement(rs.getString(2));
mod3.addElement(rs.getString(3));
mod4.addElement(rs.getString(4));
}
}
catch (SQLException c)
{
JOptionPane.showMessageDialog(null,"Error"+c.getMessage());
}
}
/**
* 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() {
jLabel1 = new javax.swing.JLabel();
jButton1 = new javax.swing.JButton();
jLabel2 = new javax.swing.JLabel();
jLabel3 = new javax.swing.JLabel();
jLabel4 = new javax.swing.JLabel();
jLabel5 = new javax.swing.JLabel();
jTextField1 = new javax.swing.JTextField();
jTextField2 = new javax.swing.JTextField();
jTextField3 = new javax.swing.JTextField();
jTextField4 = new javax.swing.JTextField();
jLabel6 = new javax.swing.JLabel();
jLabel7 = new javax.swing.JLabel();
jLabel8 = new javax.swing.JLabel();
jLabel9 = new javax.swing.JLabel();
jScrollPane1 = new javax.swing.JScrollPane();
jList1 = new javax.swing.JList();
jScrollPane2 = new javax.swing.JScrollPane();
jList2 = new javax.swing.JList();
jScrollPane3 = new javax.swing.JScrollPane();
jList3 = new javax.swing.JList();
jScrollPane4 = new javax.swing.JScrollPane();
jList4 = new javax.swing.JList();
jButton2 = new javax.swing.JButton();
jButton3 = new javax.swing.JButton();
jTextField5 = new javax.swing.JTextField();
jTextField6 = new javax.swing.JTextField();
jScrollPane5 = new javax.swing.JScrollPane();
jTextArea1 = new javax.swing.JTextArea();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jLabel1.setText(" COLORINES ");
jButton1.setText("GUARDAR");
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});
jLabel2.setText("ARTICULO");
jLabel3.setText("MARCA");
jLabel4.setText("PRECIO");
jLabel5.setText("CANTIDAD");
jTextField1.setText("jTextField1");
jTextField1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jTextField1ActionPerformed(evt);
}
});
jTextField2.setText("jTextField2");
jTextField3.setText("jTextField3");
jTextField4.setText("jTextField4");
jLabel6.setText("CANTIDAD");
jLabel7.setText("PRECIO");
jLabel8.setText("MARCA");
jLabel9.setText("ARTICULO");
jList1.setModel(new javax.swing.AbstractListModel() {
String[] strings = { "Item 1", "Item 2", "Item 3", "Item 4", "Item 5" };
public int getSize() { return strings.length; }
public Object getElementAt(int i) { return strings[i]; }
});
jScrollPane1.setViewportView(jList1);
jList2.setModel(new javax.swing.AbstractListModel() {
String[] strings = { "Item 1", "Item 2", "Item 3", "Item 4", "Item 5" };
public int getSize() { return strings.length; }
public Object getElementAt(int i) { return strings[i]; }
});
jScrollPane2.setViewportView(jList2);
jList3.setModel(new javax.swing.AbstractListModel() {
String[] strings = { "Item 1", "Item 2", "Item 3", "Item 4", "Item 5" };
public int getSize() { return strings.length; }
public Object getElementAt(int i) { return strings[i]; }
});
jScrollPane3.setViewportView(jList3);
jList4.setModel(new javax.swing.AbstractListModel() {
String[] strings = { "Item 1", "Item 2", "Item 3", "Item 4", "Item 5" };
public int getSize() { return strings.length; }
public Object getElementAt(int i) { return strings[i]; }
});
jScrollPane4.setViewportView(jList4);
jButton2.setText("BUSCAR");
jButton2.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton2ActionPerformed(evt);
}
});
jButton3.setText("BORRAR");
jButton3.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton3ActionPerformed(evt);
}
});
jTextField5.setText("jTextField5");
jTextField6.setText("jTextField6");
jTextArea1.setColumns(20);
jTextArea1.setRows(5);
jScrollPane5.setViewportView(jTextArea1);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addGap(0, 0, Short.MAX_VALUE)
.addComponent(jLabel1, javax.swing.GroupLayout.PREFERRED_SIZE, 140, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(281, 281, 281))
.addGroup(layout.createSequentialGroup()
.addGap(88, 88, 88)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jTextField5, javax.swing.GroupLayout.PREFERRED_SIZE, 97, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGroup(layout.createSequentialGroup()
.addGap(116, 116, 116)
.addComponent(jButton2)))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(jTextField6, javax.swing.GroupLayout.PREFERRED_SIZE, 116, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(jButton3)
.addGap(144, 144, 144))
.addGroup(layout.createSequentialGroup()
.addGap(67, 67, 67)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addComponent(jScrollPane5, javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jLabel2)
.addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, 121, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 45, Short.MAX_VALUE)
.addComponent(jTextField2, javax.swing.GroupLayout.PREFERRED_SIZE, 92, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(52, 52, 52)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addComponent(jLabel4)
.addGap(19, 19, 19))
.addComponent(jTextField3, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.PREFERRED_SIZE, 71, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(45, 45, 45)
.addComponent(jLabel5))
.addGroup(layout.createSequentialGroup()
.addGap(28, 28, 28)
.addComponent(jTextField4, javax.swing.GroupLayout.PREFERRED_SIZE, 89, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(30, 30, 30)
.addComponent(jButton1)))))
.addGap(34, 34, 34))
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jLabel9)
.addComponent(jScrollPane1))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jScrollPane2, javax.swing.GroupLayout.PREFERRED_SIZE, 126, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jLabel8)
.addComponent(jLabel3))
.addGap(43, 43, 43)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jScrollPane3, javax.swing.GroupLayout.PREFERRED_SIZE, 91, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jLabel7))
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(43, 43, 43)
.addComponent(jLabel6))
.addGroup(layout.createSequentialGroup()
.addGap(34, 34, 34)
.addComponent(jScrollPane4, javax.swing.GroupLayout.PREFERRED_SIZE, 71, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addGap(87, 87, 87))))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addComponent(jLabel1, javax.swing.GroupLayout.PREFERRED_SIZE, 28, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jButton2)
.addComponent(jTextField5, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jButton3)
.addComponent(jTextField6, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel9, javax.swing.GroupLayout.PREFERRED_SIZE, 14, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jLabel8)
.addComponent(jLabel7)
.addComponent(jLabel6))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jScrollPane2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jScrollPane3, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jScrollPane4, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(26, 26, 26)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel2, javax.swing.GroupLayout.PREFERRED_SIZE, 14, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jLabel3)
.addComponent(jLabel4)
.addComponent(jLabel5))
.addGap(26, 26, 26)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jTextField2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jTextField3, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jTextField4, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jButton1))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jScrollPane5, javax.swing.GroupLayout.PREFERRED_SIZE, 73, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(35, Short.MAX_VALUE))
);
pack();
}// </editor-fold>
private void jButton3ActionPerformed(java.awt.event.ActionEvent evt) {
try
{
conn=Enlace(conn); /*creo la conexion con la base de datos*/
st=conn.createStatement(); /*Especifico que hare una consulta sobre conn que contiene mi base de datos*/
st.execute("DELETE FROM informacion WHERE articulo='"+jTextField6.getText()+"'"); /*guardo en rs result set, mi consulta de toda la tabla "informacion"*/
jTextField6.setText("");
}
catch (SQLException c)
{
JOptionPane.showMessageDialog(null,"Error"+c.getMessage());
}
// TODO add your handling code here:
}
private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {
String cadena="";
try
{
conn=Enlace(conn); /*creo la conexion con la base de datos*/
st=conn.createStatement(); /*Especifico que hare una consulta sobre conn que contiene mi base de datos*/
rs=st.executeQuery("select informacion.articulo,informacion.departamento,informacion.precio,informacion.cantidad FROM informacion WHERE articulo='"+jTextField5.getText()+"';"); /*guardo en rs result set, mi consulta de toda la tabla "informacion"*/
while(rs.next()) /*mientras rs result set (contiene la tabla lista), tenga datos para leer, sigue leyendo*/
{
cadena=cadena+rs.getString(1)+" "+rs.getString(2)+" "+rs.getString(3)+" "+rs.getString(4)+"\n";
/*mod1.addElement(rs.getString(1));
mod2.addElement(rs.getString(2));
mod3.addElement(rs.getString(3));
mod4.addElement(rs.getString(4));
*/
}
jTextArea1.setText(cadena);
}
catch (SQLException c)
{
JOptionPane.showMessageDialog(null,"Error"+c.getMessage());
}
// TODO add your handling code here:
}
private void jTextField1ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
}
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
try
{
conn=Enlace(conn); /*creo la conexion con la base de datos*/
st=conn.createStatement(); /*Especifico que hare una consulta sobre conn que contiene mi base de datos*/
st.execute("INSERT INTO informacion VALUES ("+jTextField1.getText()+",'"+jTextField2.getText()+"','"+jTextField3.getText()+"','"+jTextField4.getText()+"');"); /*guardo en rs result set, mi consulta de toda la tabla "informacion"*/
jTextField1.setText("");
jTextField2.setText("");
jTextField3.setText("");
jTextField4.setText("");
}
catch (SQLException c)
{
JOptionPane.showMessageDialog(null,"Error"+c.getMessage());
}
// TODO add your handling code here:
}
/**
* @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(JProject2.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(JProject2.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(JProject2.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(JProject2.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 JProject2().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JButton jButton1;
private javax.swing.JButton jButton2;
private javax.swing.JButton jButton3;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JLabel jLabel3;
private javax.swing.JLabel jLabel4;
private javax.swing.JLabel jLabel5;
private javax.swing.JLabel jLabel6;
private javax.swing.JLabel jLabel7;
private javax.swing.JLabel jLabel8;
private javax.swing.JLabel jLabel9;
private javax.swing.JList jList1;
private javax.swing.JList jList2;
private javax.swing.JList jList3;
private javax.swing.JList jList4;
private javax.swing.JScrollPane jScrollPane1;
private javax.swing.JScrollPane jScrollPane2;
private javax.swing.JScrollPane jScrollPane3;
private javax.swing.JScrollPane jScrollPane4;
private javax.swing.JScrollPane jScrollPane5;
private javax.swing.JTextArea jTextArea1;
private javax.swing.JTextField jTextField1;
private javax.swing.JTextField jTextField2;
private javax.swing.JTextField jTextField3;
private javax.swing.JTextField jTextField4;
private javax.swing.JTextField jTextField5;
private javax.swing.JTextField jTextField6;
// This is JProject2.java
}
//这是一个名为jproject.java的包，网站把它放在同一个代码框中，但这与下一个代码分开
{{1}}
这是JProject2.java，通过netbeans将信息发送到Mysql表的接口的代码和这两者之间的java连接器
答案 0 :(得分：0)
问题是我们可能需要围绕列值的单引号 因为我们传递一个字符串，所以INSERT语句的正确功能代码是：
"INSERT INTO informacion VALUES ('"+jTextField1.getText()+"', '"+jTextField2.getText()+"', "+jTextField3.getText()+", "+jTextField4.getText()+");"
您目前在jButton1ActionPerformed方法中拥有的是
"INSERT INTO informacion VALUES ("+jTextField1.getText()+",'"+jTextField2.getText()+"','"+jTextField3.getText()+"','"+jTextField4.getText()+"');"
哪种看起来不正确。
或者您可以使用PreparedStatement PreparedStatement是一种特殊的Statement对象，具有一些有用的功能。
PreparedStatement的优点
您可以使用PreparedStatement而不是如下所示的语句：
String insertTableSQL = "INSERT INTO informacion"
+ "(articulo , departamento , precio , cantidad ) VALUES"
+ "(?,?,?,?)";
PreparedStatement preparedStatement = conn.prepareStatement(insertTableSQL);
preparedStatement.setString(1, "jTextField1.getText()");
preparedStatement.setString(2, "jTextField2.getText()");
preparedStatement.setFloat(3, Float.parseFloat("jTextField3.getText()"));
preparedStatement.setInt(4, Integer.parseInt("jTextField4.getText()"));
// execute insert SQL stetement
preparedStatement .executeUpdate();