From 8b5022cf04fb7839cb1c25ec8463e738135fcb41 Mon Sep 17 00:00:00 2001
From: Luca Ferrari <fluca1978@gmail.com>
Date: Mon, 6 Dec 2021 11:24:04 +0100
Subject: Task 1 PostgreSQL done

---
 challenge-142/luca-ferrari/postgresql/ch-1.sql | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)
 create mode 100644 challenge-142/luca-ferrari/postgresql/ch-1.sql

diff --git a/challenge-142/luca-ferrari/postgresql/ch-1.sql b/challenge-142/luca-ferrari/postgresql/ch-1.sql
new file mode 100644
index 0000000000..57de950651
--- /dev/null
+++ b/challenge-142/luca-ferrari/postgresql/ch-1.sql
@@ -0,0 +1,20 @@
+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;
-- 
cgit