Question

我想通过提供凭证编号作为搜索条件来搜索数据库，但是保证号是整数，所以我不能使用以下代码执行此操作，请为此建议一些其他代码。

  try{
            String sql = "select item_type as 'Item Type', md_by as 'Made By', model as       'Model', selling_price as 'Selling Price', purchase_price as 'Purchase Price', purchase_date as 'Purchase Date', vouch_no as 'Voucher No.', vouch_date as 'Voucher Date', record_no as 'Record No.' from purchase" where vouch_no = ?;
            ps = con.prepareStatement(sql);
            ps.setString(1 , txt_vouchno_p.getText());
            rs = ps.executeQuery();
            Table_p.setModel(DbUtils.resultSetToTableModel(rs));


        }   
        catch(SQLException ex){

                JOptionPane.showMessageDialog(null, "Error: " + ex);

        }
        catch(Exception ex){
            JOptionPane.showMessageDialog(null, "Error: " + ex);
        }

Answer 1

使用Integer#parseInt将txt_vouchno_p.getText()的值转换为int并相应地将其传递给PreparedStatement：

ps.setInt(1, Integer.parseInt(txt_vouchno_p.getText()));

在您当前的代码中看起来像是一个拼写错误，但是对于大文字String，不要害怕将它拆分成几行，编译器足够智能将其转换为单个大String } 为了你。所以，这一行：

String sql = "select item_type as 'Item Type', md_by as 'Made By', model as       'Model', selling_price as 'Selling Price', purchase_price as 'Purchase Price', purchase_date as 'Purchase Date', vouch_no as 'Voucher No.', vouch_date as 'Voucher Date', record_no as 'Record No.' from purchase" where vouch_no = ?;

应改写为：

String sql = "select item_type as 'Item Type'"
    + ", md_by as 'Made By'"
    + ", model as 'Model'"
    + ", selling_price as 'Selling Price'"
    + ", purchase_price as 'Purchase Price'"
    + ", purchase_date as 'Purchase Date'"
    + ", vouch_no as 'Voucher No.'"
    + ", vouch_date as 'Voucher Date'"
    + ", record_no as 'Record No.'"
    + " from purchase"
    + " where vouch_no = ?";

Answer 2

你的代码中有一个简单的错误（“vouch_no ...”不在字符串sql中），它应该是：

 String sql = "select item_type as 'Item Type', md_by as 'Made By', model as       'Model', selling_price as 'Selling Price', purchase_price as 'Purchase Price', purchase_date as 'Purchase Date', vouch_no as 'Voucher No.', vouch_date as 'Voucher Date', record_no as 'Record No.' from purchase where vouch_no = ?";

您可以像这样设置参数：

ps = con.prepareStatement(sql);
ps.setString(1 , Integer.parseInt(txt_vouchno_p.getText()));

通过java搜索整数类型数据库字段

2 个答案: