Using mysqli_fetch_assoc to Retrieve Query Results in PHP

In PHP, database operations are essential, and the mysqli extension is commonly used. This article explains how to use the mysqli_fetch_assoc function to fetch query results.

1. Connect to the Database

First, use mysqli_connect to establish a connection to a MySQL database. Example code:

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

$conn = mysqli_connect($servername, $username, $password, $dbname);

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

2. Query the Database

Next, execute a SELECT statement with mysqli_query. Example:

$sql = "SELECT id, name, email FROM users";
$result = mysqli_query($conn, $sql);

After the query, iterate over the result set using mysqli_fetch_assoc, which returns each row as an associative array until no rows remain.

while ($row = mysqli_fetch_assoc($result)) {
    echo "ID: " . $row["id"] . ", Name: " . $row["name"] . ", Email: " . $row["email"] . "<br>";
}

3. Full Example

The following complete script combines connection, query, and result processing with mysqli_fetch_assoc:

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

$conn = mysqli_connect($servername, $username, $password, $dbname);

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

$sql = "SELECT id, name, email FROM users";
$result = mysqli_query($conn, $sql);

if (mysqli_num_rows($result) > 0) {
    while ($row = mysqli_fetch_assoc($result)) {
        echo "ID: " . $row["id"] . ", Name: " . $row["name"] . ", Email: " . $row["email"] . "<br>";
    }
} else {
    echo "0 结果";
}

mysqli_close($conn);

Note that the database credentials and table structure should be adjusted to match your environment.

Conclusion

The article demonstrates how to retrieve query results in PHP by connecting to the database, executing a SELECT query, and looping through the result set with mysqli_fetch_assoc, simplifying data handling and improving development efficiency.