Object-oriented data access

<?PHP//Data Access//Way One: already obsolete//1. Create a connection (establish a channel), need three parameters//$db =mysql_connect ("localhost", "root", "123456");//2. Select which database to manipulate//mysql_select_db ("MyDB", $db);//3. Write SQL statements//$sql = "SELECT * from Info";//4. Execute SQL statements//$result =mysql_query ($sql);//5. Fetching data from the result set//$row =mysql_fetch_row ($result);//Var_dump ($row);//While ($row =mysql_fetch_row ($result))//{//Var_dump ($row);//}//Way Two: object-oriented approach//1. Create a Connection object//$db =new mysqli ("localhost", "root", "123456", "mydb");//2. Determine if the connection is wrong//!mysqli_connect_error () or Die ("Connection Failed");/*if (Mysqli_connect_error ()) {echo "Connection failed"; Exit ();//Quit the entire program}*///3. Write SQL statements//$sql = "Selct * from Info";//4. Execute SQL statement, if execution succeeds return result set object, False if execution fails//$result = $db->query ($sql);//5. Read the data from the result set, and add a judgment before reading to determine if result is true//if ($result)//{    //Var_dump ($result->fetch_row ());//returns an array of rows of data that is an indexed array    /*while ($row =mysql_fetch_row ($result)) {var_dump ($row); }*/    //Var_dump ($result->fetch_assoc ());//returns a row of data, returning an associative array//Var_dump ($result->fetch_all ());//returns all data, and the data is a two-dimensional array//Var_dump ($result->fetch_object ());//returns a row of data, the way the data becomes an object//}//1. Making Connection Objects//$db =new mysqli ("localhost");//Find out the info table and display it in a table$db =NewMysqli ("localhost","Root","","MyDB");!mysqli_connect_error () or Die ("Connection Failed"); $sql="SELECT * from Info"; $result= $dbquery ($sql);if($result) {$a= $resultFetch_all ();    Var_dump ($a); Echo"<table width= ' 100% ' cellpadding= ' 0 ' cellspacing= ' 0 ' border= ' 1 ' >"; Echo"<tr> <td>Code</td> <td>Name</td> <td>Sex</td> <td>nation</ td> <td>Birthday</td> </tr>"; foreach($a as$v) {echo"<tr><td>{$v [0]}</td> <td>{$v [1]}</td> <td>{$v [2]}</td> <td>{$ v[3]}</td> <td>{$v [4]}</td> </tr>"; } Echo"</table>"; } $db 1=NewMysqli ("localhost","Root","","MyDB");!mysqli_connect_error () or Die ("Connection Failed"); $sql 1="SELECT * FROM Nation"; $result= $db 1->query ($sql 1); $n= $resultFetch_all (); Var_dump ($n); Echo"<select>"; foreach($n as$v) {echo"<option value= ' {$v [0]} ' >{$v [1]}</option>"; } Echo"<select>"; ?>

Object-oriented data access