Data update

Task/URL-decoding/DuckDB/url-decoding.duckdb

@@ -0,0 +1,27 @@
+create or replace function hex2chr(pxx) as
+  replace(pxx,'%','').from_hex().decode() ;
+
+create or replace function urldecode(url) as (
+  WITH RECURSIVE cte AS (
+    -- Base case: set xx as the first sequence of %XX encodings if any
+    SELECT
+        replace(url, '+', ' ') AS decoded,
+        regexp_extract(replace(url, '+', ' '), '(%[0-9A-Fa-f]{2})+') AS xx
+    UNION ALL
+    -- Recursive case: replace the xx encodings with the decoded character(s)
+    SELECT
+        replace(decoded, xx, xx.hex2chr()) AS decoded,
+        regexp_extract(replace(decoded, xx, '  '), '(%[0-9A-Fa-f]{2})+') as xx
+    FROM cte
+    WHERE xx != ''
+  )
+  SELECT decoded FROM cte
+  WHERE xx = ''
+);
+
+SELECT s, url_decode(s), urldecode(s)
+FROM unnest( [
+  'http%3A%2F%2Ffoo%20bar%2F',
+  'google.com/search?q=%60Abdu%27l-Bah%C3%A1',
+  '%25%32%35'
+    ]) _(s);