MySQL Error 1124 is an error that occurs when you attempt to create or use a User-Defined Function (UDF) and specify a path for the shared library that contains the UDF’s code. This error reflects MySQL’s security model, which disallows the use of directory path values for the shared library to prevent potential security risks.
Understanding the Error
A User-Defined Function in MySQL is a way to extend MySQL with a new function that is not natively available. UDFs are written in a programming language like C or C++ and compiled into a shared library (.so file on Unix/Linux or .dll file on Windows). When you register a UDF in MySQL, you should only specify the name of the shared library file without any directory paths.
The error message “No paths allowed for shared library” indicates that a path was erroneously included in the UDF creation statement.
Diagnosing the Problem
To diagnose this error, inspect the CREATE FUNCTION statement you used to register the UDF. Look for any directory paths preceding the shared library name. For instance, the following statement would trigger Error 1124:
CREATE FUNCTION my_udf RETURNS INTEGER SONAME '/usr/lib/mysql/plugin/my_udf.so';The presence of /usr/lib/mysql/plugin/ in the SONAME is the cause of the error.
Fixing the Error
To resolve this issue, you will need to remove the path from the SONAME clause in the CREATE FUNCTION statement. Here’s how you can correct the error:
Example 1: Correcting the UDF Registration
Remove the path from the SONAME clause and specify only the shared library file name:
CREATE FUNCTION my_udf RETURNS INTEGER SONAME 'my_udf.so';Ensure that the shared library file is located in the directory where MySQL expects to find UDF plugins, which is typically the plugin_dir directory.
Example 2: Verifying the Plugin Directory
Check MySQL’s plugin_dir variable to confirm the location where MySQL expects to find plugin files:
SHOW VARIABLES LIKE 'plugin_dir';Make sure your .so or .dll file is in this directory.
Example 3: Moving the Shared Library
If the shared library is not in the correct directory, move it to the plugin_dir:
mv /path/to/your/my_udf.so $(mysql_config --plugindir)This command is for Unix/Linux systems. Adjust it accordingly if you’re using a different operating system.
Example 4: Ensuring Proper Permissions
After moving the shared library to the plugin_dir, ensure that MySQL has the necessary permissions to access the file:
chmod 755 /path/to/plugin_dir/my_udf.so
chown mysql:mysql /path/to/plugin_dir/my_udf.soAgain, adjust these commands for your specific environment and operating system.
Conclusion
MySQL Error 1124 is a straightforward issue to fix once you understand that MySQL does not allow paths in the SONAME clause for UDFs. By ensuring the shared library is in the correct location and removing any paths from your CREATE FUNCTION statement, you can successfully create and use UDFs in MySQL. Always remember to follow best practices for security and maintain a clean and organized plugin directory.
