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Task/Benfords-law/SQL/benfords-law.sql

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+-- Create table
+create table benford (num integer);
+
+-- Seed table
+insert into benford (num) values (1);
+insert into benford (num) values (1);
+insert into benford (num) values (2);
+
+-- Populate table
+insert into benford (num)
+  select
+    ult + penult
+  from
+    (select max(num) as ult from benford),
+    (select max(num) as penult from benford where num not in (select max(num) from benford))
+
+-- Repeat as many times as desired
+--    in Oracle SQL*Plus, press "Slash, Enter" a lot of times
+--    or wrap this in a loop, but that will require something db-specific...
+
+-- Do sums
+select
+  digit,
+  count(digit) / numbers as actual,
+  log(10, 1 + 1 / digit) as expected
+from
+  (
+    select
+      floor(num/power(10,length(num)-1)) as digit
+    from
+      benford
+  ),
+  (
+    select
+      count(*) as numbers
+    from
+      benford
+  )
+group by digit, numbers
+order by digit;
+
+-- Tidy up
+drop table benford;