From a11a02429b7dab7f63edd6ca1fff290a44855232 Mon Sep 17 00:00:00 2001
From: Jonathan Perry-Houts <jonathan@invertedearth.net>
Date: Tue, 15 May 2018 10:36:38 -0700
Subject: [PATCH] Avoid Pony/MySQL problem

MySQL throws the following with bulk deletes. Non-bulk deletes don't generate complex SQL statements, so avoid the problem.

pony.orm.dbapiprovider.OperationalError: (1093, "Table 'self' is specified twice, both as a target for 'DELETE' and as a separate source for data")
---
 supysonic/db.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/supysonic/db.py b/supysonic/db.py
index a716069..762e625 100644
--- a/supysonic/db.py
+++ b/supysonic/db.py
@@ -107,7 +107,7 @@ class Folder(PathMixin, db.Entity):
             not exists(f for f in Folder if f.parent == self) and not self.root)
         total = 0
         while True:
-            count = query.delete(bulk = True)
+            count = query.delete(bulk = False)
             total += count
             if not count:
                 return total
@@ -140,7 +140,7 @@ class Artist(db.Entity):
     @classmethod
     def prune(cls):
         return cls.select(lambda self: not exists(a for a in Album if a.artist == self) and \
-            not exists(t for t in Track if t.artist == self)).delete(bulk = True)
+            not exists(t for t in Track if t.artist == self)).delete(bulk = False)
 
 class Album(db.Entity):
     _table_ = 'album'
@@ -180,7 +180,7 @@ class Album(db.Entity):
 
     @classmethod
     def prune(cls):
-        return cls.select(lambda self: not exists(t for t in Track if t.album == self)).delete(bulk = True)
+        return cls.select(lambda self: not exists(t for t in Track if t.album == self)).delete(bulk = False)
 
 class Track(PathMixin, db.Entity):
     _table_ = 'track'