Question

使用我的代码，如果用户选中其中一个名称旁边的复选框当用户点击“保存”时，名称会保存到我的review_shared表格中。

但是我希望只保存一个选中的值一旦进入表格，现在的方式就会多次保存 - 我的意思是，如果用户回到此页面并且检查了名称并且用户点击了“保存”字样。再次。

我可以在代码中添加哪些内容，因此只会在review_shared表中保存一次？目前它看起来像这样，可以多次保存：

if(!empty($_POST['check_contacts'])) {
    foreach($_POST['check_contacts'] as $check) {

        //$_GET['id'] is the current review for which contacts are being edited, we are checking a contact to share that review with
            $insert_review_shared_command = "INSERT INTO review_shared VALUES(NULL," .$_GET['id']. ", '$user_id','$check')";

        //we want to save the checked contacts into the review_shared table
        $insert_into_review_shared_table = mysqli_query($con,$insert_review_shared_command);

    }

        //go to the main page when changes have been saved
    header('Location:volleyLogin.php');
}

    $con->close();

我认为在上面添加这样的代码会有所帮助，但事实并非如此：

        if(!empty($_POST['check_contacts'])) {

    //************************* added this in **************
                $check="";
        //if the contact in review_shared is already checked, we don't want to save it multiple times
            $already_checked = "SELECT * from review_shared WHERE user_id = '$user_id' AND contact_id = '$check' AND review_id = " .$_GET['id'];

            $already_checked_result=mysqli_query($con,$already_checked);
            $num_rows = mysqli_num_rows($already_checked_result);

            if($num_rows >= 1) {
            echo "This is already a contact";
            break;
            }

//*******************************************************

        foreach($_POST['check_contacts'] as $check) {

            //$_GET['id'] is the current review for which contacts are being edited, we are checking a contact to share that review with
                $insert_review_shared_command = "INSERT INTO review_shared VALUES(NULL," .$_GET['id']. ", '$user_id','$check')";

            //we want to save the checked contacts into the review_shared table
            $insert_into_review_shared_table = mysqli_query($con,$insert_review_shared_command);

        }

            //go to the main page when changes have been saved
        header('Location:volleyLogin.php');
    }

        $con->close();

Answer 1

break;用于循环（for，foreach，while和do-while）和switch结构，而不是来自if区块。您必须创建与 else块对应的if块，并将整个foreach循环放在那里。

// your code
if($num_rows) {
    echo "This is already a contact";
}else{
    foreach($_POST['check_contacts'] as $check) {

        //$_GET['id'] is the current review for which contacts are being edited, we are checking a contact to share that review with
        $insert_review_shared_command = "INSERT INTO review_shared VALUES(NULL," .$_GET['id']. ", '$user_id','$check')";

        //we want to save the checked contacts into the review_shared table
        $insert_into_review_shared_table = mysqli_query($con,$insert_review_shared_command);

    }
}
// your code

以下是相关参考：

http://php.net/manual/en/control-structures.break.php

如果选中，我如何确保只将值保存到表中一次？

1 个答案: