Using SQLite make a query using:

Survey:

CREATE TABLE Person (id text, personal text, family text);

CREATE TABLE Site (name text, lat real, long real);

CREATE TABLE Survey (taken integer, person text, quant text, reading real);

CREATE TABLE Visited (id integer, site text, dated text);

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2. where you are aggregating data using group by with multiple groups. (This can use concepts from Selecting Data, Combining Data, Aggregation, Calculating New Values, Sorting or Removing Duplicates, or Filtering)