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(This article is for reference only. The code may have errors due to changes in time and versions. Readers are asked to adjust by themselves)
In website development, the query function is very common. I will share it with you below. Let’s look at the PHP code implementation of a simple query function.
First, create an input box and a submit button in the HTML file:
<form action="query.php" method="post"> <input type="text" name="name" placeholder="请输入要查询的名字"> <input type="submit" name="submit" value="查询"> </form>
Then, write the SQL statement in the query.php file and output the result:
<?php // 建立数据库连接 $conn = mysqli_connect("localhost", "username", "password", "database_name"); // 获取输入框中的名字 $name = $_POST['name']; // 查询语句 $sql = "SELECT * FROM user WHERE name LIKE '%$name%'"; // 执行查询 $result = mysqli_query($conn, $sql); // 输出查询结果 if(mysqli_num_rows($result) > 0) { while($row = mysqli_fetch_assoc($result)) { echo "名字:" . $row['name'] . "<br>"; echo "年龄:" . $row['age'] . "<br>"; echo "性别:" . $row['gender'] . "<br>"; echo "<hr>"; } } else { echo "查询结果为空!"; } // 关闭数据库连接 mysqli_close($conn); ?>
Code explanation:
$_POST
. $sql
is the query statement, LIKE
represents fuzzy query, and %
represents any character. mysqli_fetch_assoc
. while
loop and mysqli_num_rows
to determine whether the query results are empty. This article only briefly introduces the PHP code implementation of the query function and does not include other security and optimization content. In actual development, you also need to pay attention to preventing security issues such as SQL injection, and optimizing the performance of query statements.
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