基本查询
select
检索表中的所有行
$users = DB::table('users')->get();
从表检索单个行(name = lilei)
$user = DB::table('users')->where('name', 'lilei')->first();
检索单个列的行(查询出 name = lilei 的 id)
$name = DB::table('users')->where('name','lilei')->pluck('id');
检索一个列值列表(单独查询这一列)
$roles = DB::table('roles')->lists('title');
该方法将返回一个数组标题即为 title。你也可以指定一个自定义的键列返回的数组
$roles = DB::table('roles')->lists('title', 'name');
指定一个Select子句进行查询
$users = DB::table('users')->select('name', 'email')->get();
$users = DB::table('users')->distinct()->get();
$users = DB::table('users')->select('name as user_name')->get();
Select子句添加到一个现有的查询 $query = DB::table('users')->select('name');
$users = $query->addSelect('age')->get();
where
$users = DB::table('users')->where('votes', '>', 100)->get();
OR
$users = DB::table('users')->where('votes', '>', 100)->orWhere('name', 'John')->get();
Where Between
$users = DB::table('users')->whereBetween('votes', array(1, 100))->get();
Where Not Between
$users = DB::table('users')->whereNotBetween('votes', array(1, 100))->get();
Where In With An Array
$users = DB::table('users')->whereIn('id', array(1, 2, 3))->get();
$users = DB::table('users')->whereNotIn('id', array(1, 2, 3))->get();
Using Where Null To Find Records With Unset Values
$users = DB::table('users')->whereNull('updated_at')->get();
Order By, Group By, And Having
$users = DB::table('users')->orderBy('name', 'desc')->groupBy('count')->having('count', '>', 100)->get();
Offset & Limit
$users = DB::table('users')->skip(10)->take(5)->get();
Joins 连接
查询构建器也可以用来编写连接语句。
Basic Join Statement
DB::table('users')
->join('contacts', 'users.id', '=', 'contacts.user_id')
->join('orders', 'users.id', '=', 'orders.user_id')
->select('users.id', 'contacts.phone', 'orders.price')
->get();
左连接语句
DB::table('users')
->leftJoin('posts', 'users.id', '=', 'posts.user_id')
->get();
DB::table('users')
->join('contacts', function($join) {
$join->on('users.id', '=', 'contacts.user_id')->orOn(...);
})
->get();
DB::table('users')
->join('contacts', function($join) {
$join->on('users.id', '=', 'contacts.user_id')
->where('contacts.user_id', '>', 5);
})
->get();
分组
有时候, 您可能需要创建更高级的where子句, 如“存在”或嵌套参数分组。Laravel query builder可以处理这些:
DB::table('users')
->where('name', '=', 'John')
->orWhere(function($query) {
$query->where('votes', '>', 100)
->where('title', '<>', 'Admin');
})
->get();
上面的查询将产生以下SQL:
select * from users where name = 'John' or (votes > 100 and title <> 'Admin')
Exists Statements
DB::table('users')
->whereExists(function($query) {
$query->select(DB::raw(1))
->from('orders')
->whereRaw('orders.user_id = users.id');
})
->get();
上面的查询将产生以下SQL:
select * from users where exists (
select 1 from orders where orders.user_id = users.id
)
聚合
查询构建器还提供了各种聚合方法,如统计,马克斯,min,avg和总和。
Using Aggregate Methods
$users = DB::table('users')->count();
$price = DB::table('orders')->max('price');
$price = DB::table('orders')->min('price');
$price = DB::table('orders')->avg('price');
$total = DB::table('users')->sum('votes');
Raw Expressions
有时您可能需要使用一个原始表达式的查询。这些表达式将注入的查询字符串,所以小心不要创建任何SQL注入点!创建一个原始表达式,可以使用DB:rawmethod:
Using A Raw Expression
$users = DB::table('users')
->select( DB::raw('count(*) as user_count, status') )
->where('status', '<>', 1)
->groupBy('status')
->get();
递增或递减一个列的值
DB::table('users')->increment('votes');
DB::table('users')->increment('votes', 5);
DB::table('users')->decrement('votes');
DB::table('users')->decrement('votes', 5);
您还可以指定额外的列更新:
DB::table('users')->increment('votes', 1, array('name' => 'lilei'));
