PHP——laravel之DB类->查询

DB类之查询：

1. 满足条件的全部获取：DB::table("表名")->where("name",">","1")->get();
2. 满足条件的第一列获取：DB::table("表名")->where("name",">","1")->first();
3. 满足条件的全部字段：DB::table("表名")->where("name",">","1")->lists("title");
4. 满足条件的单一字段：DB::table("表名")->where("name",">","1")->pluck("title");//返回二位字段值数组
   　　                             DB::table("表名")->where("name",">","1")->pluck("title","name");//返回二位字段值数组 第二个参数指定key
5. 分块查询数据列：DB::table("表名")->chunk(100,function($users){
   //$users to do $user是table中2行一次查询的结果
   //return false; 停止处理接下来的数据
   })
6. 指定查询字句：DB::table("表名")->select("name","email")->get();
7. 增加查询子句到已有查询中：$query=DB::table("表名")->select("name","email");$query->addSelect("age")->get();
8. 条件查询where和orWhere：DB::table("表名")->where("name",">","10")->orWhere("titile","=","0")->get();
9. 条件查询whereBetween和whereNotBetween：DB::table("表名")->where("name",">","10")->whereBetween("titile","=","[0,10]")->get();
10. 条件查询whereIn：DB::table("表名")->where("name",">","10")->whereIn("titile","[1,2,3]")->get();
11. 条件查询whereNull：DB::table("表名")->where("name",">","10")->whereNull("titile")->get();//未配置的值
12. 条件查询where Clauses：DB::table("表名")->where("name",">","10")->whereNameAndTitle("name",titile")->get()；
13. 排序（Drder By）,分群（Group By）及 Having:
    $users=DB::table("users")->orderBy("name","desc")->groupBy("count")->having("count",">",100)->get()
    偏移（Offset）及 限制 （Limit）
    $users=DB::table("users")->skip(10)->take(5)->get();