How to query 8 pieces of data in MySQL with php

PHP is a very popular and practical programming language that can be used for a variety of projects, from simple Java applications to large-scale web applications. For many website engineers, querying data in the database is a basic need, which allows us to better understand user behavior on the website and optimize the performance of the website. In this article, we will introduce how to use PHP to write code to query 8 pieces of data in the database.

Before you start, you need to make sure that PHP and MySQL are installed on the server. Next, we will use PHP to write a simple code to query the database and obtain data.

Here are some code examples that demonstrate how to query 8 pieces of data using PHP and MySQL:

<?php
//DB credentials
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "database_name";

//Create connection
$conn = new mysqli($servername, $username, $password, $dbname);

//Check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}

//Query statement
$sql = "SELECT * FROM table_name LIMIT 8";

//Query execution
$result = $conn->query($sql);

//Output data
if ($result->num_rows > 0) {
    //Output data of each row
    while($row = $result->fetch_assoc()) {
        echo "id: " . $row["id"]. " - Name: " . $row["name"]. " " . $row["surname"]. "<br>";
    }
} else {
    echo "0 results";
}
$conn->close();
?>

First, we need to set the user credentials for the database. You need to replace the following variables with their own values:

$servername - 数据库服务器的名称
$username - 用户名
$password - 密码
$dbname - 数据库名称

We then use PHP’s mysqli class to create a connection to the database. If the connection fails, an error is output, otherwise we perform a query operation. In this example, we ask to query all columns in the database and limit the results to 8 records.

After executing the query, we check if the result contains rows. If so, iterate through the results and output the id, name, and surname values ​​for each row. If the result is empty, the "0 results" string is output.

Finally, we close the connection to the database.

This code is very simple and easy to understand. You can change it as needed, add additional query conditions or change the formatting of the query results.

In summary, querying data in a database using PHP is a basic task, but it is crucial for web programmers. The code examples provided in this article can help you quickly understand how to use PHP to query records in the database and how to output the query results.

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