How to Troubleshoot 'Invalid MySQL Result' Errors?

MySQL Result Validation: Resolving "Invalid MySQL Result" Errors

When attempting to execute a database query and process the results using mysql_fetch_array(), it's crucial to ensure that the input result is valid. If an "invalid MySQL result" error occurs, it indicates that the provided result is not a valid resource obtained from a successful database query.

To resolve this issue, you may consider the following steps:

1. Check for Query Execution Errors:

Utilize mysql_error() to check for any errors encountered during the database query execution. This will assist in identifying the specific issue causing an invalid result.

2. Validate Database Connection:

Verify that the database connection is established successfully before executing any queries. Check the connection status using the mysqli_connect_error() function.

3. Modify the Query() Method:

Revise the query() method in your DbConnector class to incorporate error handling. In case of a failed query, generate an exception with details like the error message, query, and error number.

function query($query) {
    $this->theQuery = $query;
    $queryId = mysql_query($query, $this->link);
    if (!$queryId) {
        throw new Exception(mysql_error() . ".  Query was:\n\n" . $query . "\n\nError number: " . mysql_errno());
    }
    return $queryId;
}

By implementing these steps, you can enhance your code's robustness and effectively resolve "invalid MySQL result" errors.

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