[6.x] Add generated columns (virtual/stored) support for PostgreSQL (#…

…30971)

* Add generated columns (virtual/stored) support for PostgreSQL

* Fix StyleCI issue

src/Illuminate/Database/Schema/Grammars/PostgresGrammar.php

@@ -19,7 +19,7 @@ class PostgresGrammar extends Grammar
      *
      * @var array
      */
-    protected $modifiers = ['Collate', 'Increment', 'Nullable', 'Default'];
+    protected $modifiers = ['Collate', 'Increment', 'Nullable', 'Default', 'VirtualAs', 'StoredAs'];
 
     /**
      * The columns available as serials.
@@ -952,4 +952,32 @@ protected function modifyIncrement(Blueprint $blueprint, Fluent $column)
             return ' primary key';
         }
     }
+
+    /**
+     * Get the SQL for a generated virtual column modifier.
+     *
+     * @param  \Illuminate\Database\Schema\Blueprint  $blueprint
+     * @param  \Illuminate\Support\Fluent  $column
+     * @return string|null
+     */
+    protected function modifyVirtualAs(Blueprint $blueprint, Fluent $column)
+    {
+        if ($column->virtualAs !== null) {
+            return " generated always as ({$column->virtualAs})";
+        }
+    }
+
+    /**
+     * Get the SQL for a generated stored column modifier.
+     *
+     * @param  \Illuminate\Database\Schema\Blueprint  $blueprint
+     * @param  \Illuminate\Support\Fluent  $column
+     * @return string|null
+     */
+    protected function modifyStoredAs(Blueprint $blueprint, Fluent $column)
+    {
+        if ($column->storedAs !== null) {
+            return " generated always as ({$column->storedAs}) stored";
+        }
+    }
 }

tests/Database/DatabasePostgresSchemaGrammarTest.php

@@ -742,6 +742,26 @@ public function testAddingGeneratedAs()
         $this->assertSame('alter table "users" add column "foo" integer generated by default as identity not null', $statements[0]);
     }
 
+    public function testAddingVirtualAs()
+    {
+        $blueprint = new Blueprint('users');
+        $blueprint->integer('foo')->nullable();
+        $blueprint->boolean('bar')->virtualAs('foo is not null');
+        $statements = $blueprint->toSql($this->getConnection(), $this->getGrammar());
+        $this->assertCount(1, $statements);
+        $this->assertSame('alter table "users" add column "foo" integer null, add column "bar" boolean not null generated always as (foo is not null)', $statements[0]);
+    }
+
+    public function testAddingStoredAs()
+    {
+        $blueprint = new Blueprint('users');
+        $blueprint->integer('foo')->nullable();
+        $blueprint->boolean('bar')->storedAs('foo is not null');
+        $statements = $blueprint->toSql($this->getConnection(), $this->getGrammar());
+        $this->assertCount(1, $statements);
+        $this->assertSame('alter table "users" add column "foo" integer null, add column "bar" boolean not null generated always as (foo is not null) stored', $statements[0]);
+    }
+
     public function testAddingIpAddress()
     {
         $blueprint = new Blueprint('users');