TDBISAMFunction* __fastcall CreateFunction(Data::Db::TFieldType
      ResultType, const System::UnicodeString FunctionName)

Usage

Call the CreateFunction method to create a new custom function definition and return a reference to the function definition. The ResultType parameter specifies the resultant data type and the FunctionName parameter specifies the name of the custom function. This name is case-insensitive when referred to in filter expressions or SQL statements.