Quote: "A 1-to-many relationship between statistics and measurement_configuration tables can be established by using the fields station_european_code, component_code and measurement_european_group_code."
1. Looking at the tables it seems that 1-to-many relation should be between "measurement_configuration" and "statistics" instead other way around, which is easily noticed as those three fields are not unique in "statistics" table, and by common sense it looks like relation should be opposite from suggested.
2. If above is true, then we can't use "measurement_european_group_code" as key as it is not present in composite PRIMARY KEY in "measurement_configuration" table where we have only "measurement_european_code" which is different from "measurement_european_group_code".