From 27e8ea7025e8e6958994573cc81ba25bffb7019a Mon Sep 17 00:00:00 2001
From: Paul Trowbridge <paul@hptrow.me>
Date: Fri, 4 Nov 2022 13:37:00 -0400
Subject: [PATCH] function to add an element to an array and get all unique
 elements only

---
 postgres/jsonb_array_add_distinct.sql | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)
 create mode 100644 postgres/jsonb_array_add_distinct.sql

diff --git a/postgres/jsonb_array_add_distinct.sql b/postgres/jsonb_array_add_distinct.sql
new file mode 100644
index 0000000..577bdd9
--- /dev/null
+++ b/postgres/jsonb_array_add_distinct.sql
@@ -0,0 +1,23 @@
+CREATE OR REPLACE FUNCTION public.jsonb_array_add_distinct(_arr jsonb, _add text) RETURNS jsonb AS
+$$
+DECLARE
+    _ret jsonb;
+
+BEGIN
+
+SELECT 
+    jsonb_agg(DISTINCT x.ae)
+INTO
+    _ret
+FROM
+    (
+        SELECT jsonb_array_elements_text(_arr) ae
+        UNION ALL 
+        SELECT _add ae
+    ) x;
+
+RETURN _ret;
+
+END;
+$$
+language plpgsql