Why Are My MySQLi Queries Failing, and How Can I Troubleshoot Them?

Dealing with MySQLi Execution Failures: Exploring Common Errors

Errors like "mysqli_fetch_array(): Argument #1 must be of type mysqli_result" and "Call to a member function bind_param() on a non-object" often signal failed MySQLi queries. To resolve these issues, it's crucial to follow these guidelines:

1. Enable MySQLi Error Reporting

Always include mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT); at the start of your mysqli connection code. This ensures that MySQL errors are converted into PHP exceptions, making them easier to identify.

2. Utilize Prepared Statements

Replace all PHP variables in SQL queries with question marks and execute the query using prepared statements. This approach prevents syntax errors and enhances query security.

3. Check Error Logs

If you encounter execution failures, check the PHP error logs. On a development server, you can view errors in the browser console's Network tab. On live servers, refer to the error log for detailed information.

4. Analyze Error Messages

Read and comprehend the error message provided by MySQL. It contains valuable information about the cause of the failure, such as missing tables, incorrect syntax, or mismatched input data.

5. Basic Debugging

If the error persists, employ basic debugging techniques to rule out other potential causes:

• Check if the execution code reaches the query execution point.
• Ensure that the query is accessing the correct database.
• Verify the integrity of the input data against the database structure.

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