我需要检查框是否在数据库中存在(如果框不存在时输入的汇款ID下),如果框不存在,那么我需要显示框不存在的消息,但如果不存在,则应插入新框i已经写了一些代码,但显示错误

private void txtboxnoFocusLost(java.awt.event.FocusEvent evt) {
    DBUtil util = new DBUtil();

    try {
        Connection con = util.getConnection();
        PreparedStatement stmt = con.prepareStatement(
            "select box_no from dbo.soil_det where rm_id = ? and box_no = ?");
        stmt.setLong(1, Long.parseLong(tf_rm_id.getText()));
        stmt.setString(1, (txtboxno.getText()));
        ResultSet rs=stmt.executeQuery();
        while(rs.next()){
            rs.equals().txtboxno.getText());
        }
        JOptionPane.showMessageDialog(rootPane, "hello!S");
    } catch (Exception ex) {
        Logger.getLogger(DATAENTRY.class.getName()).log(Level.SEVERE, null, ex);
    }

最佳答案

试试这个代码

private void txtboxnoFocusLost(java.awt.event.FocusEvent evt) {
DBUtil util = new DBUtil();

try {
    Connection con = util.getConnection();
    PreparedStatement stmt = con.prepareStatement(
        "select box_no from dbo.soil_det where rm_id = ? and box_no = ?");
    stmt.setLong(1, Long.parseLong(tf_rm_id.getText()));
    stmt.setString(2, (txtboxno.getText()));
    ResultSet rs=stmt.executeQuery();
    bool recordAdded = false;
    while(!rs.next()){
       /// Do your insertion of new records
         recordAdded = true;
    }
    if( recordAdded ){
      JOptionPane.showMessageDialog(rootPane, "Record added");
    }else{
       JOptionPane.showMessageDialog(rootPane, "Record already exists");
    }
} catch (Exception ex) {
    Logger.getLogger(DATAENTRY.class.getName()).log(Level.SEVERE, null, ex);
}

10-05 21:53
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