From 9e3179fece72f199fc624aa2ee9fa7e3b7e70267 Mon Sep 17 00:00:00 2001
From: Kazuyoshi Tomita <kztomita@bit-hive.com>
Date: Thu, 1 Feb 2024 13:45:43 +0900
Subject: [PATCH] Fixed an error when $query->from is of type
 Illuminate\Database\Query\Expression.

---
 src/Illuminate/Database/Query/Builder.php   |  2 +-
 tests/Database/DatabaseQueryBuilderTest.php | 34 +++++++++++++++++++++
 2 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/src/Illuminate/Database/Query/Builder.php b/src/Illuminate/Database/Query/Builder.php
index ebb833707b11..cf5889e32a61 100755
--- a/src/Illuminate/Database/Query/Builder.php
+++ b/src/Illuminate/Database/Query/Builder.php
@@ -394,7 +394,7 @@ protected function prependDatabaseNameIfCrossDatabaseQuery($query)
             $this->getConnection()->getDatabaseName()) {
             $databaseName = $query->getConnection()->getDatabaseName();
 
-            if (! str_starts_with($query->from, $databaseName) && ! str_contains($query->from, '.')) {
+            if (is_string($query->from) && ! str_starts_with($query->from, $databaseName) && ! str_contains($query->from, '.')) {
                 $query->from($databaseName.'.'.$query->from);
             }
         }
diff --git a/tests/Database/DatabaseQueryBuilderTest.php b/tests/Database/DatabaseQueryBuilderTest.php
index cf0c8389b09b..15c701d1b3ef 100755
--- a/tests/Database/DatabaseQueryBuilderTest.php
+++ b/tests/Database/DatabaseQueryBuilderTest.php
@@ -2504,6 +2504,40 @@ public function testJoinSubWithPrefix()
         $this->assertSame('select * from "prefix_users" inner join (select * from "contacts") as "prefix_sub" on "prefix_users"."id" = "prefix_sub"."id"', $builder->toSql());
     }
 
+    public function testJoinSubWithCrossDatabaseQuery()
+    {
+        // Create another database connection and builder.
+        $connection2 = m::mock(ConnectionInterface::class);
+        $connection2->shouldReceive('getDatabaseName')->andReturn('database2');
+        $builder2 = new Builder($connection2, new Grammar, m::mock(Processor::class));
+
+        // Create subquery that use another databases.
+        // Case1: 'from' property is string
+        $subquery = $builder2
+                  ->from('posts')
+                  ->select('user_id, title');
+
+        $builder = $this->getBuilder();
+        $builder->from('users')->joinSub($subquery, 'sub', function ($join) {
+            $join->on('users.id', '=', 'sub.user_id');
+        });
+
+        $this->assertSame('select * from "users" inner join (select "user_id, title" from "database2"."posts") as "sub" on "users"."id" = "sub"."user_id"', $builder->toSql());
+
+        // Create subquery that use another databases.
+        // Case2: 'from' property is Expression
+        $subquery = $builder2
+                  ->from(new Raw('database2.posts'))  // set Expression
+                  ->select('user_id, title');
+
+        $builder = $this->getBuilder();
+        $builder->from('users')->joinSub($subquery, 'sub', function ($join) {
+            $join->on('users.id', '=', 'sub.user_id');
+        });
+
+        $this->assertSame('select * from "users" inner join (select "user_id, title" from database2.posts) as "sub" on "users"."id" = "sub"."user_id"', $builder->toSql());
+    }
+
     public function testLeftJoinSub()
     {
         $builder = $this->getBuilder();