How to Extract Column Information from Database Query Results Using mysqli_result::fetch_fields?

<?php
// Example PHP code unrelated to the article content
echo "Welcome to my PHP tutorial page!";
<?>
<p><hr></p>
<p><?php<br>
/*<br>
Title: How to Extract Column Information from Database Query Results Using mysqli_result::fetch_fields?<br>
*/</p>
<p>// When working with MySQL databases in PHP, it's often necessary to retrieve column information from query results, such as column names, data types, and lengths. The mysqli fetch_fields method provides a convenient way to extract this information.</p>
<p>// 1. Connect to the database<br>
$servername = "localhost";<br>
$username = "root";<br>
$password = "";<br>
$database = "test_db";</p>
<p>$mysqli = new mysqli($servername, $username, $password, $database);</p>
<p>if ($mysqli->connect_error) {<br>
die("Connection failed: " . $mysqli->connect_error);<br>
}</p>
<p>// 2. Execute query<br>
$sql = "SELECT id, name, email FROM users";<br>
$result = $mysqli->query($sql);</p>
<p>if ($result) {<br>
// 3. Extract column information using fetch_fields<br>
$fields = $result->fetch_fields();</p>
echo "<ul>";
foreach ($fields as $field) {
    echo "<li>";
    echo "Column Name: " . $field->name . "<br>";
    echo "Table Name: " . $field->table . "<br>";
    echo "Data Type: " . $field->type . "<br>";
    echo "Length: " . $field->length . "<br>";
    echo "Maximum Length: " . $field->max_length . "<br>";
    echo "</li><br>";
}
echo "</ul>";

// 4. Iterate through the result set
echo "<h2>Query Result Data:</h2>";
while ($row = $result->fetch_assoc()) {
    </span>echo "ID: " . $row['id'] . ", Name: " . $row['name'] . ", Email: " . $row['email'] . "<br>";
}

$result->free</span>();
</span>

} else {
echo "Query failed: " . $mysqli->error;
}

$mysqli->close();

/*
Summary:

• mysqli_result::fetch_fields() returns an array containing all column information.

• Each array element is an object with properties like name, table, type, length, etc.

• This is useful for dynamically generating tables, exporting data, or debugging database structures.
  */
  
  

  • Related Tags:

    mysqli_result