將表數據與字符串進行比較

Question

我試圖找出來自我的數據庫的數據是否與用戶輸入相匹配。我試過這個代碼，但它沒有做我需要做的事情。我希望它顯示一條消息，說明它們是否匹配。

try { 
     String find = BC.getText(); //Get text from Textfield 
     String sql = "select * from Inventory where Barcode=?"; 
     st = con.prepareStatement(sql); 
     rs = st.executeQuery(); 

     while (rs.next()) { 
      if("Barcode".equals(find)) 
      { 
       JOptionPane.showMessageDialog(null,"Matching"); 

      } 
      else JOptionPane.showMessageDialog(null,"not matching"); 
     } 

    } catch (Exception ex) { 


    } 

Answer 1

放入你想要搜索的參數。

String find = BC.getText(); //Get text from Textfield 
String sql = "select * from Inventory where Barcode=?"; 
st = con.prepareStatement(sql); 
st.setString(1, "12345678");//Set Barcode value. 
rs = st.executeQuery();