laravel 数据库之DB类

// 取回数据表的第一条数据
DB::table('table')->where('key', 'value')->first();
DB::table('table')->first();
// 从单行中取出单列数据
DB::table('users')->where('key', 'value')->pluck('id');
DB::table('name')->pluck('id');
// 取多行数据的「列数据」数组
DB::table('roles')->lists('title', 'name');
// 指定一个选择字句
DB::table('users')->select('key', 'value')->get();
DB::table('users')->distinct()->get();
DB::table('users')->select('name as user_name')->get();
// 添加一个选择字句到一个已存在的查询语句中
$query = DB::table('users')->select('name');
$users = $query->addSelect('age')->get();
// 取得数据表的所有行
DB::table('name')->get();
// 取数据表的部分数据
DB::table('users')->chunk(100, function($users) {
foreach ($users as $user){
// 逻辑编辑
}
});

// 使用 Where 运算符
DB::table('users')->where('votes', '>', 100)->get();
DB::table('users') ->where('votes', '>', 100) ->orWhere('name', 'John') ->get();
DB::table('users') ->whereBetween('votes', [1, 100])->get();
DB::table('users') ->whereNotBetween('votes', [1, 100])->get();
DB::table('users') ->whereIn('id', [1, 2, 3])->get();
DB::table('users') ->whereNotIn('id', [1, 2, 3])->get();
DB::table('users') ->whereNull('updated_at')->get();
DB::table('name')->whereNotNull('column')->get();

// 动态的 Where 字句
DB::table('users') ->whereId(1)->first();
DB::table('users') ->whereIdAndEmail(2, '12345678@qq.com') ->first();
DB::table('users') ->whereNameOrAge('Jane', 22) ->first();

// Order By, Group By, 和 Having
DB::table('users') ->orderBy('name', 'desc') ->groupBy('count') ->having('count', '>', 100) ->get();
DB::table('name')->orderBy('column')->get();
DB::table('name')->orderBy('column','desc')->get();
DB::table('name')->having('count', '>', 100)->get();

// 偏移 & 限制
$users = DB::table('users')->skip(10)->take(5)->get();

// 基本的 Join 声明语句
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();
// Left Join 声明语句
DB::table('users')
->leftJoin('posts', 'users.id', '=', 'posts.user_id')
->get();
// select * from users where name = 'John' or (votes > 100 and title <> 'Admin')
DB::table('users')
->where('name', '=', 'John')
->orWhere(function($query) { $query->where('votes', '>', 100) ->where('title', '<>', 'Admin'); })
->get();

//聚合
DB::table('users')->count();
DB::table('orders')->max('price');
DB::table('orders')->min('price');
DB::table('orders')->avg('price');
DB::table('users')->sum('votes');

DB::table('name')->remember(5)->get();
DB::table('name')->remember(5, 'cache-key-name')->get();
DB::table('name')->cacheTags('my-key')->remember(5)->get();
DB::table('name')->cacheTags(array('my-first-key','my-second-key'))->remember(5)->get();
DB::table('users')
->select(DB::raw('count(*) as user_count, status'))
->where('status', '<>', 1)
->groupBy('status')
->get();

// 返回行
DB::select('select * from users where id = ?', array('value'));
DB::insert('insert into foo set bar=2');
DB::update('update foo set bar=2');
DB::delete('delete from bar');
// 返回 void
DB::statement('update foo set bar=2');
// 在声明语句中加入原始的表达式
DB::table('name')->select(DB::raw('count(*) as count, column2'))->get();

Inserts / Updates / Deletes / Unions / Pessimistic Locking

// 插入
$id = DB::table('users')->insertGetId(
['email' => '12345678@qq.com', 'votes' => 0]
);
DB::table('users')->insert([
['email' => '12345678@qq.com', 'votes' => 0],
['email' => '12345678@qq.com', 'votes' => 0]
]);

// 更新
DB::table('users') ->where('id', 1) ->update(['votes' => 1]);
DB::table('users')->increment('votes');
DB::table('users')->increment('votes', 5);
DB::table('users')->decrement('votes');
DB::table('users')->decrement('votes', 5);
DB::table('users')->increment('votes', 1, ['name' => 'John']);

// 删除
DB::table('users')->where('votes', '<', 100)->delete();
DB::table('users')->delete();
DB::table('users')->truncate();

// 运行数据库查询语句
$results = DB::select('select * from users where id = ?', [1]);
$results = DB::select('select * from users where id = :id', ['id' => 1]);
// 运行普通语句
DB::statement('drop table users');
// 监听查询事件
DB::listen(function($sql, $bindings, $time){ code_here; });
// 数据库事务处理
① 第一种
DB::transaction(function(){
DB::table('users')->update(['votes' => 1]);
DB::table('posts')->delete();
});
②第二种
DB::beginTransaction();
DB::rollback();
DB::commit();