Online Documentation for SQL Manager for MySQL
Use the Edit tab of UDF Editor to add/edit a user-defined function and specify its definition.
Enter a name for the new UDF, or view the name of the UDF being edited.
Use the drop-down list to select the return type of the UDF.
Set the name of the file containing the function that will be used by the UDF.
Check the Aggregate option to make the function an aggregate one.
Note: For the UDF mechanism to work, functions must be written in C or C++ and your operating system must support dynamic loading.