Why is MySQL reporting a warning \'No index used in query/prepared statement\' and causing a fatal error in PHP?

Error: "No index used in query/prepared statement"

When executing a SQL query that does not use an index, MySQL may issue a warning indicating "No index used in query/prepared statement". This warning suggests that the performance of the query could be improved by adding an appropriate index to the table.

In the provided PHP code, despite the warning, the fatal error is not related to MySQL. Instead, it is caused by the following factors:

• MySQL reports warnings for various events, including benign conditions.
• The code uses mysqli_report(MYSQLI_REPORT_ALL), which elevates warnings to exceptions.
• The PHP code does not catch the resulting mysqli_sql_exception exception, leading to a fatal error.

To address this issue, you have two options:

Option 1: Adjust MySQLi Reporting

You can modify the mysqli_report() setting to exclude warnings. For example, you could use:

<code class="php">mysqli_report(MYSQLI_REPORT_STRICT); // Report errors only
mysqli_report(MYSQLI_REPORT_OFF); // Disable all reporting</code>

Option 2: Handle Exceptions

Alternatively, you can properly handle the exception by enclosing your database code in a try{} block and catching the mysqli_sql_exception exception with a catch(){} block. This allows you to handle the error gracefully without it becoming fatal:

<code class="php">try {
    // Database code, including prepare, execute, etc.
} catch (mysqli_sql_exception $e) {
    // Handle the exception here.
}</code>

The above is the detailed content of Why is MySQL reporting a warning \'No index used in query/prepared statement\' and causing a fatal error in PHP?. For more information, please follow other related articles on the PHP Chinese website!