在 MySQL， PHP 中选择一个属性 - select an attribute in mysql, php

select an attribute in mysql, php

本文关键字：一个属性选择 MySQL PHP | 更新日期: 2023-09-27

我刚开始学习phpMyAdmin和mysql。这里有一个问题：我想在我的"学生"表中选择一些东西，它回显结果。但是当我检查时，它返回 0 行用于搜索。但我的数据库中有它。这是我的代码：

$conn = new mysqli($servername, $username, $password, $dbname);
    $params="@name varchar(30)";
    $paramslist="@name='$name%";
    $sql = "SELECT  name,address,city,birthday FROM student WHERE NAME=@NAME";
    $dbsql = "EXEC sp_executesql
      N'$sql',
      N'$params',
      $paramslist";
    $result = $conn->query($sql);
    ECHO $result->num_rows;

我不知道问题出在哪里。谢谢你的帮助。

$sql = "SELECT  name,address,city,birthday FROM student WHERE name=".$name;
$result = $conn->query($sql);
echo $result->num_rows();

这是对

我有用的预准备语句

// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}
$name='Veshraj Joshi';
$stmt = $conn->prepare("SELECT  name,address,city,birthday FROM student WHERE NAME=?");
/* bind parameters for markers */
$stmt->bind_param("s", $name);
/* execute query */
$stmt->execute();
$result = $stmt->get_result();
/* now you can fetch the results into an array */
while ($student = $result->fetch_assoc()) {
    // use your $student array as you would with any other fetch
    echo $student['address'].'<br>';
}

下面使用预准备语句。在包含用户输入时，应始终使用预准备语句，以防止 SQL 注入攻击。

每次执行fetch()时，结果都绑定到bind_result()指定的变量

$conn = new mysqli($servername, $username, $password, $dbname);
$query = "SELECT name,address,city,birthday FROM student WHERE name=?";
$stmt = $conn->prepare($query);
$searchTerm = "%$name%";
$stmt->bind_param('s', $searchTerm);
$stmt->execute();
$stmt->bind_result($resultName, $resultAddress, $resultCity, $resultBirthday);
while($stmt->fetch())
{
    echo $resultName . " " . $resultAddress . " " . $resultCity . "<br/>";
}