From 9e4e7cee1209b57bfb12183e1d010b15615d63b3 Mon Sep 17 00:00:00 2001
From: kiddyu <58631254@qq.com>
Date: Tue, 14 May 2024 21:14:01 +0800
Subject: [PATCH] fix: `belongsToMany` relation withCount

---
 src/relations/belongs-to-many.js | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/src/relations/belongs-to-many.js b/src/relations/belongs-to-many.js
index 5fc33d7..9267487 100644
--- a/src/relations/belongs-to-many.js
+++ b/src/relations/belongs-to-many.js
@@ -300,6 +300,27 @@ class BelongsToMany extends compose(
   //     this.touch();
   //   }
   // }
+
+  getRelationExistenceQuery(query, parentQuery, columns = ['*']) {
+    if (parentQuery.getQuery()._single.table == query.getQuery()._single.table) {
+      return this.getRelationExistenceQueryForSelfJoin(query, parentQuery, columns);
+    }
+
+    this.performJoin(query);
+
+    return super.getRelationExistenceQuery(query, parentQuery, columns);
+  }
+
+  getRelationExistenceQueryForSelfJoin(query, parentQuery, columns = ['*']) {
+    const hash = this.getRelationCountHash();
+    query.select(columns).from(this.related.getTable() + ' as ' + hash);
+
+    this.related.setTable(hash);
+
+    this.performJoin(query);
+
+    return super.getRelationExistenceQuery(query, parentQuery, columns);
+  }
 }
 
 module.exports = BelongsToMany;
\ No newline at end of file