Question

MainClass .java

public class MainClass 
{

    public String StrUrl="jdbc:mysql://localhost/vivek";


    public String StrUid;
    public String StrPwd= "";

    public static String StrUser;

    public MainClass() {
        this.StrUid = "root";
    }


}

Addproducts.java

private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         
      String proid="";
        proid=productid.getText();

        String proname="";
       proname=productname.getText();

        String purcst="";
       purcst=purchasecost.getText();

        if (proid.isEmpty()==true)
        {
         JOptionPane.showMessageDialog(null,"Enter User Name");
         return;
        }

        if (proname.isEmpty()==true)
        {
         JOptionPane.showMessageDialog(null,"Enter Password");
         return;
        }
        try
        {
            //get database connection details
            MainClass mc=new MainClass();

             //open connection
            Connection connection;
            connection=DriverManager.getConnection(mc.StrUrl,mc.StrUid,mc.StrPwd);
           String str="";
            str="INSERT INTO login('uname', 'password') VALUES (?, ?)";
           PreparedStatement pst=connection.prepareStatement(str);
           pst.setString(1, proid);
           pst.setString(2, proname);
           ResultSet rs;
           rs=pst.executeQuery();
    }                                        
    catch(Exception e){
        System.err.println(e);
        System.exit(1);
                      }
 }

java.sql.SQLException: Can not issue data manipulation statements with executeQuery().
Java Result: 1
 i tried
 rs=pst.executeUpdate();
error: incompatible types: int cannot be converted to ResultSet
rs=pst.executeUpdate();

Answer 1

您需要使用executeUpdate而不是executeQuery，但这会返回受此更改影响的行数，例如

try (Connection connection=DriverManager.getConnection(mc.StrUrl,mc.StrUid,mc.StrPwd)) {
    String str="";
    str="INSERT INTO login('uname', 'password') VALUES (?, ?)";
    try (PreparedStatement pst=connection.prepareStatement(str)) {
        pst.setString(1, proid);
        pst.setString(2, proname);
        int count=pst.executeQuery();
        System.out.println(count + " rows changed");
    }
} catch (SQLException exp) {
    exp.printStackTrace();
}

如果您想从数据库中检索值，则需要使用select语句，例如......

try (Connection connection=DriverManager.getConnection(mc.StrUrl,mc.StrUid,mc.StrPwd)) {
    String str="";
    str="select * from login where name = ? and password = ?";
    try (PreparedStatement pst=connection.prepareStatement(str)) {
        pst.setString(1, proid);
        pst.setString(2, proname);
        try (ResultSet rs = pst.executeQuery()) {
            while (rs.next() {
                //... Process each result...
            }
        }
    }
} catch (SQLException exp) {
    exp.printStackTrace();
}

仔细查看JDBC(TM) Database Access了解更多详情......

我想使用swing mysql插入数据

1 个答案: