Support updateFrom() on PostgreSQL

src/Query/Grammars/Traits/CompilesPostgresExpressions.php

@@ -3,6 +3,7 @@
 namespace Staudenmeir\LaravelCte\Query\Grammars\Traits;
 
 use Illuminate\Database\Query\Builder;
+use Illuminate\Support\Str;
 
 trait CompilesPostgresExpressions
 {
@@ -44,6 +45,38 @@ public function getBindingsForUpdate(Builder $query, array $bindings, array $val
         return $this->prepareBindingsForUpdate($bindings, $values);
     }
 
+    /**
+     * Compile an update from statement into SQL.
+     *
+     * @param \Illuminate\Database\Query\Builder $query
+     * @param array $values
+     * @return string
+     */
+    public function compileUpdateFrom(Builder $query, $values)
+    {
+        $compiled = parent::compileUpdateFrom($query, $values);
+
+        return (string) Str::of($compiled)
+                           ->prepend($this->compileExpressions($query, $query->expressions), ' ')
+                           ->trim();
+    }
+
+    /**
+     * Prepare the bindings for an update statement.
+     *
+     * @param array $bindings
+     * @param array $values
+     * @return array
+     */
+    public function prepareBindingsForUpdateFrom(array $bindings, array $values)
+    {
+        $values = array_merge($bindings['expressions'], $values);
+
+        unset($bindings['expressions']);
+
+        return parent::prepareBindingsForUpdateFrom($bindings, $values);
+    }
+
     /**
      * Compile a delete statement into SQL.
      *

src/Query/Traits/BuildsExpressionQueries.php

@@ -204,7 +204,7 @@ public function insertUsing(array $columns, $query)
     /**
      * Update records in the database.
      *
-     * @param  array  $values
+     * @param array $values
      * @return int
      */
     public function update(array $values)
@@ -217,4 +217,21 @@ public function update(array $values)
             $this->grammar->getBindingsForUpdate($this, $this->bindings, $values)
         ));
     }
+
+    /**
+     * Update records in a PostgreSQL database using the update from syntax.
+     *
+     * @param array $values
+     * @return int
+     */
+    public function updateFrom(array $values)
+    {
+        $this->applyBeforeQueryCallbacks();
+
+        $sql = $this->grammar->compileUpdateFrom($this, $values);
+
+        return $this->connection->update($sql, $this->cleanBindings(
+            $this->grammar->prepareBindingsForUpdateFrom($this->bindings, $values)
+        ));
+    }
 }

tests/QueryTest.php

@@ -389,6 +389,22 @@ public function testUpdateWithLimit()
         $this->assertEquals([1, 0], DB::table('posts')->orderBy('id')->pluck('views')->all());
     }
 
+    public function testUpdateFrom()
+    {
+        if ($this->database !== 'pgsql') {
+            $this->markTestSkipped();
+        }
+
+        DB::table('posts')
+          ->withExpression('u', DB::table('users')->where('id', '>', 1))
+          ->join('u', 'u.id', '=', 'posts.user_id')
+          ->updateFrom([
+              'views' => DB::raw('"u"."followers"'),
+          ]);
+
+        $this->assertEquals([0, 20], DB::table('posts')->orderBy('id')->pluck('views')->all());
+    }
+
     public function testDelete()
     {
         if ($this->database === 'mariadb') {

tests/TestCase.php

@@ -24,6 +24,7 @@ protected function setUp(): void
         Schema::create('users', function (Blueprint $table) {
             $table->increments('id');
             $table->unsignedInteger('parent_id')->nullable();
+            $table->unsignedBigInteger('followers');
             $table->timestamps();
         });
 
@@ -36,9 +37,9 @@ protected function setUp(): void
 
         Model::unguard();
 
-        User::create(['parent_id' => null]);
-        User::create(['parent_id' => 1]);
-        User::create(['parent_id' => 2]);
+        User::create(['parent_id' => null, 'followers' => 10]);
+        User::create(['parent_id' => 1, 'followers' => 20]);
+        User::create(['parent_id' => 2, 'followers' => 30]);
 
         Post::create(['user_id' => 1]);
         Post::create(['user_id' => 2]);