fix: upsert with composite unique index

system/Database/Postgre/Builder.php

@@ -469,9 +469,8 @@ protected function _upsertBatch(string $table, array $keys, array $values): stri
                     return ($index->type === 'UNIQUE' || $index->type === 'PRIMARY') && $hasAllFields;
                 });
 
-                foreach (array_map(static fn ($index) => $index->fields, $allIndexes) as $index) {
-                    $constraints[] = current($index);
-                    // only one index can be used?
+                foreach ($allIndexes as $index) {
+                    $constraints = $index->fields;
                     break;
                 }
 

system/Database/SQLite3/Builder.php

@@ -151,8 +151,8 @@ protected function _upsertBatch(string $table, array $keys, array $values): stri
                     return ($index->type === 'PRIMARY' || $index->type === 'UNIQUE') && $hasAllFields;
                 });
 
-                foreach (array_map(static fn ($index) => $index->fields, $allIndexes) as $index) {
-                    $constraints[] = current($index);
+                foreach ($allIndexes as $index) {
+                    $constraints = $index->fields;
                     break;
                 }
 

tests/_support/Database/Migrations/20160428212500_Create_test_tables.php

@@ -47,6 +47,15 @@ public function up(): void
             'value' => ['type' => 'VARCHAR', 'constraint' => 400, 'null' => true],
         ])->addKey('id', true)->createTable('misc', true);
 
+        // Team members Table (composite key)
+        $this->forge->addField([
+            'team_id'    => ['type' => 'INTEGER', 'constraint' => 3],
+            'person_id'  => ['type' => 'INTEGER', 'constraint' => 3],
+            'role'       => ['type' => 'VARCHAR', 'constraint' => 40],
+            'status'     => ['type' => 'VARCHAR', 'constraint' => 40],
+            'created_at' => ['type' => 'DATETIME', 'null' => true],
+        ])->addUniqueKey(['team_id', 'person_id'])->createTable('team_members', true);
+
         // Database Type test table
         // missing types:
         //   TINYINT,MEDIUMINT,BIT,YEAR,BINARY,VARBINARY,TINYTEXT,LONGTEXT,

tests/_support/Database/Seeds/CITestSeeder.php

@@ -107,6 +107,20 @@ public function run(): void
                     'value' => 'ടൈപ്പ്',
                 ],
             ],
+            'team_members' => [
+                [
+                    'team_id'   => 1,
+                    'person_id' => 22,
+                    'role'      => 'member',
+                    'status'    => 'active',
+                ],
+                [
+                    'team_id'   => 1,
+                    'person_id' => 33,
+                    'role'      => 'mentor',
+                    'status'    => 'active',
+                ],
+            ],
             'type_test' => [
                 [
                     'type_varchar'    => 'test',

tests/system/Database/Live/MetadataTest.php

@@ -47,6 +47,7 @@ protected function setUp(): void
             $prefix . 'user',
             $prefix . 'job',
             $prefix . 'misc',
+            $prefix . 'team_members',
             $prefix . 'type_test',
             $prefix . 'empty',
             $prefix . 'secondary',

tests/system/Database/Live/UpsertTest.php

@@ -448,7 +448,7 @@ public function testUpsertBatchWithOnConflictAndUpdateFields(): void
         $this->assertSame('El Salvador', $data[4]->country);
     }
 
-    public function testUpsertWithMatchingDataOnUniqueIndexandPrimaryKey(): void
+    public function testUpsertWithMatchingDataOnUniqueIndexAndPrimaryKey(): void
     {
         $data = [
             'id'      => 6,
@@ -607,6 +607,36 @@ public function testUpsertBatchMultipleConstraints(): void
         }
     }
 
+    /**
+     * @see https://github.com/codeigniter4/CodeIgniter4/issues/9450
+     */
+    public function testUpsertBatchCompositeUniqueIndex(): void
+    {
+        $data = [
+            [
+                'team_id'   => 1,
+                'person_id' => 22,
+                'role'      => 'leader',
+                'status'    => 'active',
+            ],
+            [
+                'team_id'   => 1,
+                'person_id' => 33,
+                'role'      => 'member',
+                'status'    => 'active',
+            ],
+        ];
+
+        // uses (team_id, person_id) - composite unique index
+        $this->db->table('team_members')->upsertBatch($data);
+
+        $this->seeInDatabase('team_members', ['team_id' => 1, 'person_id' => 22, 'role' => 'leader']);
+        $this->dontSeeInDatabase('team_members', ['team_id' => 1, 'person_id' => 22, 'role' => 'member']);
+
+        $this->seeInDatabase('team_members', ['team_id' => 1, 'person_id' => 33, 'role' => 'member']);
+        $this->dontSeeInDatabase('team_members', ['team_id' => 1, 'person_id' => 33, 'role' => 'mentor']);
+    }
+
     public function testSetBatchOneRow(): void
     {
         $data = [

user_guide_src/source/changelogs/v4.6.1.rst

@@ -32,6 +32,7 @@ Bugs Fixed
 
 - **CURLRequest:** Fixed an issue where multiple header sections appeared in the CURL response body during multiple redirects from the target server.
 - **Cors:** Fixed a bug in the Cors filter that caused the appropriate headers to not be added when another filter returned a response object in the ``before`` filter.
+- **Database:** Fixed a bug in ``Postgre`` and ``SQLite3`` handlers where composite unique keys were not fully taken into account for ``upsert`` type of queries.
 
 See the repo's
 `CHANGELOG.md <https://github.com/codeigniter4/CodeIgniter4/blob/develop/CHANGELOG.md>`_