How to Properly Handle Errors in MySQLi Prepared Statements?

MySQLi Prepared Statements: Error Handling Clarification

When using prepared statements with MySQLi, it can be unclear how best to handle error reporting. This article aims to clarify the proper error handling approach.

Return Value of prepare() vs. execute()

The return value of prepare() only indicates whether the SQL statement preparation was successful. It does not detect execution errors. Therefore, it is necessary to check the return value of execute() as well.

Example:

if ($stmt_test->prepare("INSERT INTO testtable VALUES (23,44,56)")) {
    if ($stmt_test->execute()) {
        echo "Statement executed successfully.";
    } else {
        echo("Execution failed: " . $stmt_test->error . "<br>");
    }
    $stmt_test->close();
} else {
    echo("Statement preparation failed: " . $stmt_test->error . "<br>");
}

Additional Error Checking

While the return value of execute() handles most errors, it is also advisable to check the errno property of the statement after execution. This ensures that any errors that may have occurred during execution are caught.

Example:

if ($stmt_test->execute()) {
    if (!$stmt_test->errno) {
        echo "Statement executed successfully.";
    } else {
        echo("Additional error occurred: " . $stmt_test->error . "<br>");
    }
    $stmt_test->close();
} else {
    echo("Execution failed: " . $stmt_test->error . "<br>");
}

Simplified Error Reporting

To greatly simplify error reporting, you can also use the mysqli_report() function. By setting the MYSQLI_REPORT_ERROR and MYSQLI_REPORT_STRICT flags, all MySQLi errors will be reported as PHP exceptions.

Example:

mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);

$stmt = $mysqli->prepare("INSERT INTO testtable VALUES (?,?,?)");
$stmt->bind_param('iii', $x, $y, $z);
$stmt->execute();

This method eliminates the need for explicit error checking in your code.

The above is the detailed content of How to Properly Handle Errors in MySQLi Prepared Statements?. For more information, please follow other related articles on the PHP Chinese website!