Java Form Suchmethode nicht funktioniert - (kann das member_id aus der Datenbank Mitgliedertabelle nicht fein)

Question

i eine Klasse Anruf Mitglied habe ich einen Methodenaufruf „public Mitglied searchByName (String key)“ in membermanager Klasse Ich habe eine andere JFrame die eine Suchtaste hat (Typ Mausklick)

in meinem Mitglieder-Datenbank gibt es ein Mitglied Anruf 123 (member_id)/Primärschlüssel

, wenn ich 123 ein und aus Java UI suchen sie sagt: „Kein Mitglied gefunden“

überprüfen Sie bitte meine Codierung und helfen Sie mir, dieses Problem zu beheben, danke Ihnen allen! :) database (lmsjason- table member)

package UIDesignLMS; 


public class member { 

    private String m_memberid; 
    private String m_membername; 
    private String m_dob; 
    private String m_address; 
    private String m_contact; 

    public member(){ 


    } 

    public member(String memberid, String membername, String dob, String address, String contact){ 
     m_memberid = memberid; 
     m_membername = membername; 
     m_dob = dob; 
     m_address = address; 
     m_contact = contact; 

    } 
    public void setId(String memberid){ 
     m_memberid = memberid; 
    } 
    public String getId(){ 
     return m_memberid; 
    } 
    public void setName(String membername){ 
     m_membername = membername; 
    } 
    public String getName(){ 
     return m_membername; 
    } 
    public void setDob(String dob){ 
     m_dob = dob; 
    } 
    public String getDob(){ 
     return m_dob; 
    } 
    public void setAddress(String address){ 
     m_address = address; 
    } 
    public String getAddress(){ 
     return m_address; 
    } 
    public void setContact(String contact){ 
     m_membername = contact; 
    } 
    public String getContact(){ 
     return m_contact; 
    } 



} 

package UIDesignLMS; 

import java.sql.Connection; 
import java.sql.DriverManager; 
import java.sql.PreparedStatement; 
import java.sql.ResultSet; 
import java.sql.SQLException; 
import java.sql.Statement; 

public class membermanager { 

    Connection conn = null; 
    PreparedStatement pst = null; 
    ResultSet re = null; 

    private ViewMemberUI view; 

    public membermanager() { 
     //load the database driver 
     conn = MysqlConnect.ConnectDB(); 
    } 



    public member searchByName(String key) { 
     Connection conn; 

     member Member = new member(); 
     try { 
      conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/lmsjason","root",""); 
      Statement stmt = conn.createStatement(); 
      ResultSet rs = stmt.executeQuery("Select * from member where Member_ID like '%\" + key + \"%' "); 
      while (rs.next()) { 

       Member = new member(rs.getString("Member_ID"), rs.getString("Name"),rs.getString("DOB"),rs.getString("Address"),rs.getString("Contact")); 

      } 
      conn.close(); 
     } catch (SQLException ex) { 
      System.out.println(ex); 
     } 

     return Member; 
    } 
    } 

private void jLabel7MouseClicked(java.awt.event.MouseEvent evt) {          
     // Search 
     if ("".equals(textmemberid.getText())) { 
      JOptionPane.showMessageDialog(null,"Member ID cannot be empty"); 

     } else { 
      member Member = manager.searchByName(textmemberid.getText()); 
      if (Member.getId() == null) { 
       JOptionPane.showMessageDialog(null,"No Member found!"); 
      } else { 
       textname.setText(Member.getName()); 
       textdob.setText(Member.getDob()); 
       textaddress.setText(Member.getAddress()); 
       textcontact.setText(Member.getContact()); 


      } 

     } 
    }  

/* 
* Data Base Connection 
*/ 
package UIDesignLMS; 
import java.sql.*; 
import javax.swing.*; 


public class MysqlConnect { 
    Connection conn=null; 
    public static Connection ConnectDB(){ 
     try { 
      Class.forName("com.mysql.jdbc.Driver"); 
      Connection conn=DriverManager.getConnection("jdbc:mysql://localhost:3306/lmsjason","root",""); 
      //JOptionPane.showMessageDialog(null, "Connected to database"); 
      return conn; 
     } catch (Exception e) { 
      JOptionPane.showMessageDialog(null, e); 
      return null; 
     } 
    } 
} 

Answer 1

Warum haben Sie einfach nicht PrepapredStatement es ist hilfreicher und sicheres Beispiel:

conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/lmsjason", "root", ""); 
PreparedStatement stm = conn.prepareStatement("Select * from member where Member_ID like ? "); 
stm.setString(1, key); 
ResultSet rs = stm.executeQuery(); 
while (rs.next()) { 
    Member = new member(rs.getString("Member_ID"), rs.getString("Name"), 
      rs.getString("DOB"), rs.getString("Address"), rs.getString("Contact")); 

} 

Sie müssen keine Anführungszeichen gesetzt '' mit PrepapredStatement

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