php連接mysql數據庫

步驟

• 連接數據庫

       $link = mysqli_connect('localhost','root','123456');

• 判斷/返回連接狀態

       if(!$link){

       echo "不兒，tm卧槽～數據庫連接失敗";

}

• 設置連接字符集

      mysqli_set_charset($link,'utf8')

• 選擇數據庫

     mysqli_select_db($link,'warmwinterI')

• 准備sql語句

     $sql = "select * from mycoachinfo"

• 發送sql語句

     $res = mysqli_query($link,$sql)

• 處理結果集

     $result = mysqli_fetch_assoc($res)//返回值是關聯數組，執行一次，往下讀一行

　  var_dump($result)

• 關閉數據庫釋放資源

     mysqli_close($link)

 綜合演練

<?php
  $link = mysqli_connect('127.0.0.1','root','wenwajiao'); //注意，主機域名務必寫為127.0.0.1如果是localhost肯定會出幺蛾子！！！
 
 if ($link)
 {
     mysqli_set_charset($link,'utf8');
     mysqli_select_db($link,"oldpassion");
     $sql =  "select * from loginfo";
     $res = mysqli_query($link,$sql);
     while($rows = mysqli_fetch_assoc($res)){
        var_dump($rows);
        echo "<br/>";   
   }
 };

 $sql2 = "select * from loginfo";
 $res = mysqli_query($link,$sql2);
 $count= mysqli_num_rows($res);
 echo $count."<br/>";
 echo "上面是關聯數組"."<br/>";
 echo "==============================="."<br/>";
 echo "下面是索引關聯數組"."<br/>";
 while($workout = mysqli_fetch_array($res))
 {
     var_dump($workout);
   echo "<br/>";
 }
?>

• mysqli_num_rows//返回查詢的行數
• mysqli_fetch_array//返回一個既有索引又有關聯的數組

• mysqli_affected_rows//返回刪除，修改等操作受影響的行數

<?php $link=mysqli_connect('127.0.0.1','root','wenwajiao'); if ($link) { mysqli_set_charset($link,'utf8'); mysqli_select_db($link,'oldpassion'); $sql2 = "insert into loginfo values(4, 'xxd','徐曉冬','xxd')"; $res = mysqli_query($link,$sql2); $duwa = mysqli_affected_rows($link); echo $duwa."<br/>"; } ?>

• mysqli_insert_id//返回自增主鍵的值

<?php $link=mysqli_connect('127.0.0.1','root','wenwajiao'); if ($link) { mysqli_set_charset($link,'utf8'); mysqli_select_db($link,'oldpassion'); $id = mysqli_insert_id($link); echo $id; $sql2 = "insert into loginfo values(4, 'xxd','徐曉冬','xxd')"; echo mysqli_insert_id($link)."<br/>"; $res = mysqli_query($link,$sql2); $duwa = mysqli_affected_rows($link); echo $duwa."<br/>"; } ?>