laravel5.5中查询构造器的使用
//查询构造器新增数据: public function query1() { /* $bool=DB::table('student')->insert( ['name'=>'小李','age'=>12] ); var_dump($bool);*/ //获取插入的id /* $ids = DB::table('student')->insertGetId( ['name' => 'php', 'age' => 22] ); var_dump($ids);*/ $bool = DB::table('student')->insert([ ['name' => '小李001', 'age' => 12], ['name' => '小李002', 'age' => 121] ] ); var_dump($bool); } //查询构造器更新数据: public function query2() { /* $num=DB::table('student') ->where('id',1004) ->update(['age'=>101]); var_dump($num);*/ //自增1 /* $num=DB::table('student')->increment('age');*/ //自增3 /* $num=DB::table('student')->increment('age',3);*/ //自减1 /*$num=DB::table('student')->decrement('age');*/ //自减3 /* $num=DB::table('student')->increment('age',3); var_dump($num);*/ //带条件自减 /* $num=DB::table('student') ->where('id',1004) ->decrement('age',3); var_dump($num);*/ $num = DB::table('student') ->where('id', 1004) ->increment('age', 3, ['name' => '小王']); var_dump($num); } //使用查询构造器删除数据: public function query3() { /* $num=DB::table('student') ->where('id','>=',1008) ->delete(); var_dump($num);*/ //清空数据表 DB::table('student')->truncate(); } //使用查询构造器查询数据: public function query4() { /* $num=DB::table('student')->insert([ ['id'=>1001,'name'=>'name1','age'=>18], ['id'=>1002,'name'=>'name2','age'=>19], ['id'=>1003,'name'=>'name3','age'=>28], ['id'=>1004,'name'=>'name4','age'=>38], ['id'=>1005,'name'=>'name5','age'=>78] ]); var_dump($num);*/ //get(); 获取表中所有数据 /* $students=DB::table('student')->get(); dd($students);*/ //first() 获取第一条数据: /*$students=DB::table('student') ->orderBy('id','desc') ->first(); dd($students);*/ //where查询数据: /*$students=DB::table('student') ->where('id','>=',1002) ->get(); dd($students);*/ //加多个条件进行查询 /*$students=DB::table('student') ->whereRaw('id>=? and age>?',[1003,38]) ->get(); dd($students);*/ //pluck() /*$names=DB::table('student') ->pluck('name'); dd($names);*/ //lists 5.3之后已经弃用 /* $names=DB::table('student') ->lists('name','id'); dd($names);*/ //select() 指定查找: /*$students=DB::table('student') ->select('id','name','age')->get(); dd($students);*/ //chunk: echo '<pre>'; $students = DB::table('student') ->orderBy('id', 'asc') ->chunk(2, function ($students) { var_dump($students); return false; //查询出一组数据出来: }); } //查询构造器中的聚合函数: public function query5() { //count() 统计数据数量 /*$num=$num=DB::table('student')->count(); var_dump($num);*/ /*$max=$num=DB::table('student')->max('age'); var_dump($max);*/ /*$min=$num=DB::table('student')->max('age'); var_dump($min);*/ /*$avg=$num=DB::table('student')->avg('age'); var_dump($avg);*/ $sum = $num = DB::table('student')->sum('age'); var_dump($sum); }