


How to Troubleshoot mysqli_query Error in PHP When Using w3schools Tutorial?
Oct 21, 2024 am 07:47 AMUsing w3schools Tutorial Results in Error
Question:
Despite following the w3schools tutorial, I'm encountering an error in line 13 (mysqli_query) while attempting to insert data using PHP and MySQL. I've explored StackOverflow but was unable to identify the issue. Can someone assist me in troubleshooting this code?
Answer:
Warning: Avoid relying on w3schools for technical information. Their resources frequently contain inaccuracies.
The error in line 13 is caused by an incorrect parameter passed to mysqli_query. The first parameter should be a connection identifier rather than a connection string.
According to the mysqli_query documentation, the correct format is:
<code class="php">mysqli_query($link, $query);</code>
where:
- $link is the MySQL connection identifier
- $query is the SQL query to be executed
Modified Code:
<code class="php"><?php // Establish a MySQL connection $mysqli = mysqli_connect("localhost", "root", "", "web_table"); // Check for connection errors if (mysqli_connect_errno()) { echo "Failed to connect to MySQL: " . mysqli_connect_error(); exit; } // Execute the INSERT query, ensuring the connection identifier is used $result = mysqli_query($mysqli, 'INSERT INTO web_formitem (ID, formID, caption, key, sortorder, type, enabled, mandatory, data) VALUES (105, 7, Tip izdelka (6), producttype_6, 42, 5, 1, 0, 0)'); // Check for insert success if ($result) { echo "<p>Insert successful</p>"; } else { echo "<p>Insert failed</p>"; }</code>
Note: Additionally, enclose column names in backticks (`) since some of your column names are reserved words in MySQL.
The above is the detailed content of How to Troubleshoot mysqli_query Error in PHP When Using w3schools Tutorial?. For more information, please follow other related articles on the PHP Chinese website!

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