How to operate the database for fuzzy deletion in PHP

PHP is a very powerful programming language that can implement many functions, among which database-oriented operations are one of the most common application scenarios. During the development process, we often need to delete data in the database. In some cases, we need to perform fuzzy deletion, that is, delete data that meets certain conditions. In this article, I will share with you how to use PHP to perform database fuzzy deletion.

1. Connect to the database

Before performing database operations, you need to connect to the database first. You can use PHP's built-in mysqli function to connect. The specific code is as follows:

$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDB";

// 创建连接
$conn = mysqli_connect($servername, $username, $password, $dbname);

// 检查连接是否成功
if (!$conn) {
    die("Connection failed: " . mysqli_connect_error());
}

In the above code, $servername fills in the database host name; $username and $password fill in the database user name and password respectively; $dbname fills in the database to be operated Database name. After the connection is successful, we can proceed with the next operation.

2. Realize fuzzy deletion

In the database, we can use SQL statements to perform deletion operations. There is a fuzzy query operation in SQL statements, which is to use the LIKE clause to query. In fuzzy deletion, we can also use the LIKE clause for deletion operations. The specific code is as follows:

// 设置删除条件
$keyword = "keyword"; // 要删除的关键词
$sql = "DELETE FROM table_name WHERE column_name LIKE '%$keyword%'";

// 执行删除操作
if (mysqli_query($conn, $sql)) {
    echo "Record deleted successfully";
} else {
    echo "Error deleting record: " . mysqli_error($conn);
}

In the above code, $keyword fills in the keywords to be deleted, $sql constructs the SQL statement, and % means matching any character. Through the above SQL statement, all data that meets the conditions can be deleted. After performing the delete operation, use the mysqli_query function to check whether the delete was successful.

3. Full code

The complete code is as follows:

$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDB";

// 创建连接
$conn = mysqli_connect($servername, $username, $password, $dbname);

// 检查连接是否成功
if (!$conn) {
    die("Connection failed: " . mysqli_connect_error());
}

// 设置删除条件
$keyword = "keyword"; // 要删除的关键词
$sql = "DELETE FROM table_name WHERE column_name LIKE '%$keyword%'";

// 执行删除操作
if (mysqli_query($conn, $sql)) {
    echo "Record deleted successfully";
} else {
    echo "Error deleting record: " . mysqli_error($conn);
}

// 关闭连接
mysqli_close($conn);

4. Notes

• When performing database operations, pay attention to SQL injection attacks.
• When using fuzzy deletion, pay attention to the integrity and correctness of the data to avoid accidental deletion.

Summary:

This article introduces how to use PHP to perform database fuzzy deletion, focusing on the use of the LIKE clause. In addition, we also need to pay attention to SQL injection attacks and data integrity and correctness. Hope this helps PHP developers.

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