From 6f255cb0891e552223beb3f8c2fba47b270f5840 Mon Sep 17 00:00:00 2001
From: "Grot (@grafanabot)" <43478413+grafanabot@users.noreply.github.com>
Date: Mon, 5 Sep 2022 16:29:56 +0200
Subject: [PATCH] LibraryElements: Fix inability to delete library panels under
 MySQL (#54600) (#54711)

Closes #53456

(cherry picked from commit 65c3ad6721622d1c7af0ee526b2745b2141bf6a4)

Co-authored-by: kay delaney <45561153+kaydelaney@users.noreply.github.com>
---
 pkg/services/libraryelements/database.go | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/pkg/services/libraryelements/database.go b/pkg/services/libraryelements/database.go
index b2596650442..a6563ef756e 100644
--- a/pkg/services/libraryelements/database.go
+++ b/pkg/services/libraryelements/database.go
@@ -28,11 +28,14 @@ SELECT DISTINCT
 	, (SELECT COUNT(connection_id) FROM ` + models.LibraryElementConnectionTableName + ` WHERE element_id = le.id AND kind=1) AS connected_dashboards`
 )
 
+// redundant SELECT to trick mysql's optimizer
 const deleteInvalidConnections = `
 DELETE FROM library_element_connection
 WHERE connection_id IN (
-	SELECT connection_id as id FROM library_element_connection
-	WHERE element_id=? AND connection_id NOT IN (SELECT id as connection_id from dashboard)
+	SELECT connection_id FROM (
+		SELECT connection_id as id FROM library_element_connection
+		WHERE element_id=? AND connection_id NOT IN (SELECT id as connection_id from dashboard)
+	) as dummy
 )`
 
 func getFromLibraryElementDTOWithMeta(dialect migrator.Dialect) string {