java - java mysql插入语法错误

Question

我在 con=createConnection(); 处收到语法错误；在 netbeans ide 中，我想将记录插入 mysql 数据库。怎么能纠正这个？

private void btnlogActionPerformed(java.awt.event.ActionEvent evt) {                                       

         user=txtuser.getText();
      char[] pass=jPasswordField1.getPassword();
             String passString=new String(pass);
            **![con =createConnection();][1]**
             try{    

String str="INSERT INTO login(username,Password) VALUES ('" + user + "','" + passString + "')";
java.sql.PreparedStatement statement=con.prepareStatement(str); 
statement.setString(1,user);
    statement.setString(2,passString);
statement.executeUpdate();
            }
            catch(Exception e){
                JOptionPane.showMessageDialog(null,"Exception: "+ e.toString());
            }

public static void main(String args[]) {
try {
            Class.forName("com.mysql.jdbc.Driver");
            String connectionUrl = "jdbc:mysql://localhost/Stock?"+
                                   "user=root&password=";
            Connection con = DriverManager.getConnection(connectionUrl);

        } catch (SQLException e) {
            JOptionPane.showMessageDialog(null,"SQL Exception: "+ e.toString());
        } catch (ClassNotFoundException cE) {
            JOptionPane.showMessageDialog(null,"Class Not Found Exception: "+ cE.toString());
        }

Answer 1

尝试这个，

 String str="INSERT INTO login(username,Password) VALUES (?,?)";
 java.sql.PreparedStatement statement=con.prepareStatement(str); 
 statement.setString(1,user);
 statement.setString(2,passString);
 statement.executeUpdate();

Answer 2

什么是con，你有 createConnection() 静态方法，会给你连接？

con =createConnection();

如果您正在使用PreparedStatement和设置参数，您应该在这样的查询中有占位符

String str = "INSERT INTO login(username,Password) VALUES (?, ?)";