Task 1 PostgreSQL done

1 files changed, 20 insertions, 0 deletions

diff --git a/challenge-142/luca-ferrari/postgresql/ch-1.sql b/challenge-142/luca-ferrari/postgresql/ch-1.sql
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index 0000000000..57de950651
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+++ b/challenge-142/luca-ferrari/postgresql/ch-1.sql
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+CREATE OR REPLACE FUNCTION
+  f_divisors_last_digit( m int, n int )
+  RETURNS SETOF int
+AS $CODE$
+  WITH RECURSIVE numbers AS (
+    SELECT 1 as num
+     UNION
+    SELECT num + 1
+      FROM numbers
+     WHERE num + 1 <= m )
+  , divisors AS (
+    SELECT num as div
+      FROM numbers
+      WHERE m % num = 0 )
+  SELECT count(*)
+  FROM divisors
+  WHERE div::text LIKE ( '%' || n::text );
+
+  $CODE$
+  LANGUAGE sql;