[10.x] Allow adding column constraints in migrations (incomplete)

src/Illuminate/Database/Schema/Blueprint.php

@@ -1673,6 +1673,23 @@ protected function createIndexName($type, array $columns)
         return str_replace(['-', '.'], '_', $index);
     }
 
+    /**
+     * Add a check constraint to the table.
+     *
+     * @param $checkName
+     * @param $constraint
+     * @return Fluent
+     */
+    public function check($checkName, $constraint)
+    {
+        return $this->addCommand('check', compact('checkName', 'constraint'));
+    }
+
+    public function dropCheck($checkName)
+    {
+        return $this->addCommand('dropCheck', compact('checkName'));
+    }
+
     /**
      * Add a new column to the blueprint.
      *

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

@@ -578,6 +578,34 @@ public function compileTableComment(Blueprint $blueprint, Fluent $command)
         );
     }
 
+    /**
+     * Compile a table level check command.
+     *
+     * @param Blueprint $blueprint
+     * @param Fluent $command
+     * @return string
+     */
+    public function compileCheck(Blueprint $blueprint, Fluent $command)
+    {
+        $table = $this->wrapTable($blueprint);
+
+        return sprintf('alter table %s add constraint %s check (%s)',
+            $table,
+            $this->wrap($command->checkName),
+            $command->constraint
+        );
+    }
+
+    public function compileDropCheck(Blueprint $blueprint, Fluent $command)
+    {
+        $table = $this->wrapTable($blueprint);
+
+        return sprintf('alter table %s drop constraint %s',
+            $table,
+            $this->wrap($command->checkName)
+        );
+    }
+
     /**
      * Quote-escape the given tables, views, or types.
      *