To create a schema variant you call SchemaVariantCreate followed by a call to set some data into it with the appropriate function. Until you have set data into the newly created schema variant the type of the schema variant will be SystemType::Undefined. Calling schema variant functions on undefined schema variants may fail.
When you are finished with a schema variant call SchemaVariantDelete to free the schema variant.
Setting/Changing
You can set/change the value and type of a schema variant with the following calls