From bf9d1166d617474756786b313df401db3757a8d7 Mon Sep 17 00:00:00 2001
From: Martin Kraft <martin@upspin.org>
Date: Wed, 18 Jan 2023 19:41:13 -0500
Subject: [PATCH] MM-49688: Handles an empty mysql.time_zone_name table.
 (#22093)

---
 store/sqlstore/channel_store.go | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/store/sqlstore/channel_store.go b/store/sqlstore/channel_store.go
index 5d6b9e83f3..d480efdd7c 100644
--- a/store/sqlstore/channel_store.go
+++ b/store/sqlstore/channel_store.go
@@ -4661,19 +4661,27 @@ func (s SqlChannelStore) PostCountsByDuration(channelIDs []string, sinceUnixMill
 	if loc == "Local" {
 		loc = "UTC"
 	}
+	var format string
 	if s.DriverName() == model.DatabaseDriverMysql {
 		if duration == model.PostsByDay {
-			unixSelect = `DATE_FORMAT(CONVERT_TZ(FROM_UNIXTIME(Posts.CreateAt / 1000), 'GMT', '` + loc + `'),'%Y-%m-%d') AS duration`
+			format = `%Y-%m-%d`
 		} else {
-			unixSelect = `DATE_FORMAT(CONVERT_TZ(FROM_UNIXTIME(Posts.CreateAt / 1000), 'GMT', '` + loc + `'),'%Y-%m-%dT%H') AS duration`
+			format = `%Y-%m-%dT%H`
 		}
+		unixSelect = fmt.Sprintf(`DATE_FORMAT(
+			COALESCE(
+				CONVERT_TZ(FROM_UNIXTIME(Posts.CreateAt / 1000), 'GMT', '%s'),
+				FROM_UNIXTIME(Posts.CreateAt / 1000)
+			),
+		'%s') AS duration`, loc, format)
 		propsQuery = `(JSON_EXTRACT(Posts.Props, '$.from_bot') IS NULL OR JSON_EXTRACT(Posts.Props, '$.from_bot') = 'false') AND (JSON_EXTRACT(Posts.Props, '$.from_webhook') IS NULL OR JSON_EXTRACT(Posts.Props, '$.from_webhook') = 'false') AND (JSON_EXTRACT(Posts.Props, '$.from_plugin') IS NULL OR JSON_EXTRACT(Posts.Props, '$.from_plugin') = 'false') AND (JSON_EXTRACT(Posts.Props, '$.from_oauth_app') IS NULL OR JSON_EXTRACT(Posts.Props, '$.from_oauth_app') = 'false')`
 	} else if s.DriverName() == model.DatabaseDriverPostgres {
 		if duration == model.PostsByDay {
-			unixSelect = fmt.Sprintf(`TO_CHAR(TO_TIMESTAMP(Posts.CreateAt / 1000) AT TIME ZONE '%s', 'YYYY-MM-DD') AS duration`, loc)
+			format = "YYYY-MM-DD"
 		} else {
-			unixSelect = fmt.Sprintf(`TO_CHAR(TO_TIMESTAMP(Posts.CreateAt / 1000) AT TIME ZONE '%s', 'YYYY-MM-DD"T"HH24') AS duration`, loc)
+			format = `YYYY-MM-DD"T"HH24`
 		}
+		unixSelect = fmt.Sprintf(`TO_CHAR(TO_TIMESTAMP(Posts.CreateAt / 1000) AT TIME ZONE '%s', '%s') AS duration`, loc, format)
 		propsQuery = `(Posts.Props ->> 'from_bot' IS NULL OR Posts.Props ->> 'from_bot' = 'false') AND (Posts.Props ->> 'from_webhook' IS NULL OR Posts.Props ->> 'from_webhook' = 'false') AND (Posts.Props ->> 'from_oauth_app' IS NULL OR Posts.Props ->> 'from_oauth_app' = 'false') AND (Posts.Props ->> 'from_plugin' IS NULL OR Posts.Props ->> 'from_plugin' = 'false')`
 	}
 	query := sq.