Basic operation of the TP framework link database

<?PHPnamespaceAdmin\controller; use Think\controller; classMaincontroller extends Controller { Publicfunction Showlist () {echo"Big Apple Mall"; }
     Publicfunction Test () {//Data Access//Build Model Objects$nation = D ("Nation"); //Enquiry//$a = $nation->select ();//check all, return associative array//$a = $nation->select ("n001"); //$a = $nation->select ("n001,n002");//The Select method is checked by the primary key value.//$a = $nation->find ("n002");//Find method can look up a piece of data//consistent Operation//$a = $nation->where ("Name= ' Miao '")->select ();//where represents the condition//$a = $nation->where ("Name= ' Han ' or name= ' Manchu '")->select ();//multiple conditions can be written//$a = $nation->table ("Car")->select ();//table can be used to switch tables//$a = $nation->table ("Car")->field ("name")->select ();//$a = $nation->field ("name")->select ();//field method for querying fields//$a = $nation->table ("Car")->order ("Code desc")->select ();//Order for sorting//$a = $nation->table ("Car")->limit (3,3)->select ();//Limit Paging method limit (3,3) means skipping 3 strips to fetch 3//$a = $nation->table ("Car")->page (3,3)->select ();//Page (3,3) means 3rd 3rd article//$a = $nation->table ("Car")->field ("Brand,avg (Price)")->group ("Brand")->select ();//Group query: Query the classification of the average price of different classes named Brand//$a = $nation->table ("Car")->field ("Brand,avg (Price)")->group ("Brand")->having ("avg (PRICE>50)") )->select ();//Group query: Query the classification of different classes named brand with average price greater than 50//$a = $nation->alias (' a ')->field ("B.code as ' Code ', b.name as ' Name ', a.name as ' national ')->join (" Info B on a.code= B.nation ")->select ();//Conditional Query//$a = $nation->table (' car ')->distinct (True)->field (' brand ')->select ();//distinct is to go to re-query: The query indicates that the list in car for brand to go heavy//$a = $nation->where ("code= ' n001 '")->getfield ("name");//GetField is the value of a column (which indicates that the name column in the Nation column is named code=n001)//$a = $nation->count ();//count indicates a few data in the Nation table//$a = $nation->table ("Car")->avg (price);//The Avg method represents the average number of columns (price) in the car table.//$a = $nation->table ("Car")->max (price);//The Max method represents the maximum value of the column (price) in the car table//$a = $nation->table (' car ')->min (price);//The min method represents the minimum value of the column (price) in the car table//$a = $nation->table (' car ')->sum (price);//The /sum method represents the sum of the columns (price) in the car table//$sql = "SELECT * from info";//You can use the original SQL statement//$a = $nation->query ($sql);//query statements are executed using the Queries method//$sql = "INSERT into nation values (' n011 ', ' Korean ')"; //$a = $nation->execute ($sql);//Execute means to perform additions, deletions, changes//var_dump ($a); //$attr =array ("Code" = "n012", "Name" = "Dulong");//Array mode: Must be an associative array//$a = $nation->add ($attr);//add data in the form of an array//var_dump ($a);//If 1 is returned successfully//Add using AR Method (Entity class database access Class connection Class)//$nation->code= "n087"; //$nation->name= "Russian"; //$nation->add (); //indicates a 5-second jump to the registration page if the registration is successful (comment the 237 lines in/thinkphp/lrbrary/think/db/lite.class.php)//$this->redirect (' Zhuce ', Array (), 5, ' page jump ... ');
        
        
        
    }
     Publicfunction Zhuce () {//Implement two logic//1. Display registration page 2. Add content to the database
    if(Empty ($_post)) {//Show Page$ This-Show (); }
        Else{$n=d ("Nation"); $n->create ();//Automatic collection of forms must have post data
        
        ///$n->name= "Hello";
$z= $nAdd (); if($z) {//Show Page$ This->success ("Add Success","Zhuce"); }
        Else
            {
        //the default jump for the error page is to return to the previous page, usually without setting$ This->error ("Add failed! "); }
        }    
        
    }
    
     Publicfunction Canshu ($id =0)
    {
    //Pass-through value: 1. Can write directly//$id =$_get["id"]; //echo $id; //2. Can give a formal parameter ($id =0)
echo $id; }
     
}

Error (Comment 237 lines in/thinkphp/lrbrary/think/db/lite.class.php)

Basic operation of the TP framework link database