PHP操作MySQL數(shù)據(jù)庫，實現(xiàn)查詢數(shù)據(jù)并輸出到web頁面

<?php     // 連接數(shù)據(jù)庫     $mysqli = mysqli_connect("localhost","root","123",&#39;student&#39;);     //mysqli_close($con);     $mysqli ? print &#39;yes!<br>':print?"no!<br>";  ????$sql?=?$mysqli?-&gt;?query('use?student'); ????$sql?=?$mysqli?-&gt;?query('set?name?utf8');  ????//?創(chuàng)建數(shù)據(jù)表 ????$sql?=?$mysqli?-&gt;?query("create?table?hacker( ????????id?char(6)?not?null, ????????name?char(8)?not?null, ????????chinese?float?not?null, ????????math?float?not?null, ????????english?float?not?null ????)"); ????if($sql?==?true){ ????????echo?'成功創(chuàng)建hacker表！<br>'; ????}else{ ????????echo?'創(chuàng)建hacker表失敗！'.$mysqli-&gt;error.'<br>'; ????}  ????//?添加數(shù)據(jù)——hacker ????//?$sql??=?"insert?into?hacker?values('1','張三','10','20','30');";? ????//?$sql??.=?"insert?into?hacker?values('2','李四','66','77','88');";? ????//?$sql?.=?"insert?into?hacker?values('3','王二','55','44','33');";? ????//?$sql?.=?"insert?into?hacker?values('4','麻子','22','55','77')";? ????//?$rows?=?$mysqli-&gt;affected_rows; ????//?if($rows?==?3){ ????//?????echo?"添加數(shù)據(jù)成功。<br>"; ????//?}else{ ????//?????echo?'添加失敗。'.$mysqli-&gt;error."<br>"; ????//?}  ????$sql?=?$mysqli?-&gt;?query("insert?into?hacker ????????values('2','李四','66','77','88') ????"); ????$rows?=?$mysqli-&gt;affected_rows; ????if($rows?==?1){ ????????echo?"添加數(shù)據(jù)成功。<br>"; ????}else{ ????????echo?'添加失敗。'.$mysqli-&gt;error."<br>"; ????} ????$sql?=?$mysqli?-&gt;?query("insert?into?hacker ????????values('3','王二','55','44','33') ????"); ????$rows?=?$mysqli-&gt;affected_rows; ????if($rows?==?1){ ????????echo?"添加數(shù)據(jù)成功。<br>"; ????}else{ ????????echo?'添加失敗。'.$mysqli-&gt;error."<br>"; ????} ????$sql?=?$mysqli?-&gt;?query("insert?into?hacker ????????values('4','麻子','22','55','77') ????"); ????$rows?=?$mysqli-&gt;affected_rows; ????if($rows?==?1){ ????????echo?"添加數(shù)據(jù)成功。<br>"; ????}else{ ????????echo?'添加失敗。'.$mysqli-&gt;error."<br>"; ????}  ????//?數(shù)據(jù)查詢 ????$sql?=?$mysqli-&gt;query("select?*?from?hacker"); ????if($sql){ ????????//?echo?'有數(shù)據(jù)！<br>'; ????????$rows?=?$sql-&gt;num_rows; ????????echo?'查詢結果共有'.$rows.'條記錄<br>'; ????????echo?"