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When developing PHP applications, the mysqli::debug method helps debug problems related to connections and queries of MySQL databases. However, in some cases, you may encounter error messages similar to the following:
Fatal error: Uncaught mysqli_sql_exception: Invalid option string
This error usually indicates that there is a problem with the parameter passing of the mysqli::debug method. In this article, we will explore common causes of this error and provide solutions.
mysqli::debug is a PHP function that is mainly used to display debugging information to help developers understand the interaction with MySQL database. This method can pass in a string containing debugging options to help developers view detailed information about database connections and queries.
For example, you might enable debug mode with the following code:
mysqli::debug("d:t:o,/tmp/mysql.trace");
This code enables the database tracking function and saves the output information to the specified file.
When you encounter an Invalid option string error, it is usually because the string passed to mysqli::debug is incorrect. The parameter requirement for mysqli::debug is a valid debug option string. This error usually originates from the following situations:
The parameters of mysqli::debug must follow a specific format. Generally, the debug option string should include the debug type (such as d represents the database), the output method (such as t represents the output to the file), and other optional parameters. If the string format does not meet the requirements, an error will be reported.
Correct example:
mysqli::debug("d:t:o,/tmp/mysql.trace");
Example of error:
mysqli::debug("d:o,,/tmp/mysql.trace");
The above code may cause Invalid option string errors due to the lack of necessary parameters or incorrect separators.
If the debug information needs to be output to the network address, make sure the URL is in the correct format. For example, suppose you are uploading a log file to a server (such as http://example.com/logs ), but if the format is written incorrectly, it may also lead to a similar error.
Correct example:
mysqli::debug("d:t:o,http://m66.net/logs/mysql.trace");
The order of parameters of mysqli::debug is very important. Any swap order practice may cause the program to fail to parse the option string correctly. Therefore, it is important to ensure that the parameter order meets the requirements.
Some older PHP versions may not fully support all the features of the mysqli::debug method. If you are using an older PHP version, it is recommended to upgrade to a newer version to avoid this problem.
For the above possible error causes, the following are some common solutions:
First, make sure the option string you passed to mysqli::debug is formatted correctly. Generally, debugging options should follow the following format:
Debug type:Output Type:Options
For example, the following is a valid debug option string:
mysqli::debug("d:t:o,/tmp/mysql.trace");
In this string:
d means enabling database debugging.
t means output to file.
o is the path to the output file.
If you plan to upload debug information to the server, make sure the URL is in the correct format:
mysqli::debug("d:t:o,http://m66.net/logs/mysql.trace");
If your PHP version is older and may not support certain options, it is recommended to upgrade to a newer version that supports mysqli::debug . You can check the PHP version and upgrade:
php -v
If the above method does not solve the problem, you can check the PHP error log for more details about the failure of the mysqli::debug call. Through the log file, you can discover other error messages that may cause the problem.
