Question

在我的大学数据库项目中，我的SQL中有一个自动增量字段滚动号。我想要的是，当新的录取发生并插入学生记录时，它会在同一页面上显示所有发现，包括卷号。然而，尽管我付出了最大努力，但它在卷号中返回0。

以下是代码：

<?php

$con = mysqli_connect("localhost", "root", "") or die("conection error");
mysqli_select_db($con, "hamdard university") or die("dbase error");

if (isset($_POST['subbtn'])) {

    $r      = "SELECT RollNo FROM admission_form";
    $result = mysqli_query($con, $r);
    if (mysqli_query($con, $r)) {
        $last_id = mysqli_insert_id($con);
    }


    $n = $_POST['txtname'];
    $f = $_POST['txtfac'];
    $s = $_POST['txtsem'];

    $sql = "insert into admission_form(name,faculty,semester)values                ('$n','$f','$s')";
    mysqli_query($con, $sql);



    echo "<table border=1>
            <th>RollNo</th>
            <th>Name</th>
            <th>Faculty</th>
            <th>Semester</th>";



    echo "<tr>";

    echo "<td>";
    echo $last_id;
    echo "</td>";

    echo "<td>";
    echo $n;
    echo "</td>";

    echo "<td>";
    echo $f;
    echo "</td>";

    echo "<td>";
    echo $s;
    echo "</td>";

    echo "<br>";


}
?>

<html>

<head></head>

<body>
    <form name="f1" action="" method="POST">
        RollNo:
        <input type="text" name="txtroll" readonly> Name:
        <input type="text" name="txtname"> Faculty:
        <input type="text" name="txtfac"> Semester:
        <input type="text" name="txtsem">
        <input type="submit" value="done" name="subbtn">
    </form>
</body>

</html>

Answer 1

INSERT查询后需要获取$ last_id

$sql="insert into admission_form(name,faculty,semester)values ...
mysqli_query($con,$sql);
$last_id = mysqli_insert_id($con);

Answer 2

您错误放置了插入查询。将其更改为：

<?php

$con=mysqli_connect("localhost","root","")or die("conection error");
mysqli_select_db($con,"hamdard university")or die("dbase error");

if(isset($_POST['subbtn']))
{

 $sql="insert into admission_form(name,faculty,semester)values                ('$n','$f','$s')";

if (mysqli_query($con, $sql)) 
{
$last_id = mysqli_insert_id($con);
}


$n=$_POST['txtname'];
$f=$_POST['txtfac'];
$s=$_POST['txtsem'];



$r="SELECT RollNo FROM admission_form";
$result=mysqli_query($con, $r);


echo        "<table border=1>
        <th>RollNo</th>
        <th>Name</th>
        <th>Faculty</th>
        <th>Semester</th>";



    echo "<tr>";

    echo "<td>";
    echo $last_id;
    echo "</td>";

    echo "<td>";
    echo $n;
    echo "</td>";

    echo "<td>";
    echo $f;
    echo "</td>";

    echo "<td>";
    echo $s;
    echo "</td>";   

    echo "<br>";


}
?>

<html>
<head></head>
<body>

<form name="f1" action="" method="POST">

RollNo:<input type="text" name="txtroll" readonly>
Name:<input type="text" name="txtname">
Faculty:<input type="text" name="txtfac">
Semester:<input type="text" name="txtsem">
<input type="submit" value="done" name="subbtn">

</form>
</body>
</html>

Answer 3

试试这个：

$mysqli = new mysqli(SQLI_SERVER, MYSQLI_USER, MYSQLI_PWD, MYSQLI_DBNAME);
if ($result = $mysqli->query("INSERT INTO admission_form(name, facility,semester) VALUES..) {
    echo 'The ID is: '.$mysqli->insert_id;
}

Answer 4

您在此页面中遇到了一些问题。

如前所述，INSER查询必须在select之前。
如果您执行“SELECT RollNo FROM admission_form”，您将在admission_form中获得所有现有的RollNo，而不是最新的。如果这是一个带有自动增量的int（接缝为），你应该“SELECT max（RollNo）FROM admission_form”。
您不需要执行上述选择，因为mysqli_insert_id会获取上次查询中插入的ID。
您可能无法在表格中看到结果，因为它位于HTML标题上，但它应位于页面正文中。
您创建的表格未“关闭”。

你应该好好接受下面的代码。

<HTML>
<HEAD></HEAD>
<BODY>
<?php
$con=mysqli_connect("localhost","root","")or die("conection error");
mysqli_select_db($con,"hamdard university")or die("dbase error");

if(isset($_POST['subbtn']))
{
  $n=$_POST['txtname'];
  $f=$_POST['txtfac'];
  $s=$_POST['txtsem'];

  $sql="insert into admission_form(name,faculty,semester) values                ('$n','$f','$s')";

  if (mysqli_query($con, $r)) 
  {
    $last_id = mysqli_insert_id($con);
  }

echo        "<table border=\"1\"><th>RollNo</th> <th>Name</th> <th>Faculty</th> <th>Semester</th>";

    echo "<tr>";

    echo "<td>";
    echo $last_id;
    echo "</td>";

    echo "<td>";
    echo $n;
    echo "</td>";

    echo "<td>";
    echo $f;
    echo "</td>";

    echo "<td>";
    echo $s;
    echo "</td>";   

    echo "</tr></table>";


}
?>

<form name="f1" action="" method="POST">

RollNo:<input type="text" name="txtroll" readonly>
Name:<input type="text" name="txtname">
Faculty:<input type="text" name="txtfac">
Semester:<input type="text" name="txtsem">
<input type="submit" value="done" name="subbtn">

</form>
</body>
</html>

如何在php中显示mysql的自动增量数据

4 个答案: