Laravel 5 与 Postgresql

我正在用postgres作为数据库开发Laravel 5.我已经配置了postgres 9.4和pgAdmin III，它们工作正常.当我try 运行"迁移"时，它会给我带来错误:

[PDOException]
could not find driver

这是我的数据库.php

'default' => 'pgsql',

'pgsql' => [            'driver'   => 'pgsql',          
                        'host'     => '127.0.0.1',          
                        'database' => 'fms',            
                        'username' => 'postgres',           
                        'password' => 'root',           
                        'charset'  => 'utf8',           
                        'prefix'   => '',           
                        'schema'   => 'public',         ],

Initially I though, it was due to configuration of postgres on windows 7 but I tried with plain php it works perfect

<?php
   $host        = "host=127.0.0.1";
   $port        = "port=5432";
   $dbname      = "dbname=fms";

   $db = pg_connect( "$host $port $dbname user=postgres password=root"  );
   if(!$db){
      echo "Error : Unable to open database\n";
   } else {
      echo "Opened database successfully\n";
   }
?>

I’ve enabled php_pgsql and php_pdo_sql in wamp as well. I’m not sure how to fix this on laravel 5.