《php和mysql web开发》笔记——第11章 使用MySQL从Web访问数据库

建立连接：

mysqli::__construct ([ string$host =ini_get("mysqli.default_host") [, string$username= ini_get("mysqli.default_user") [, string$passwd= ini_get("mysqli.default_pw") [, string $dbname= "" [, int$port =ini_get("mysqli.default_port") [, string$socket= ini_get("mysqli.default_socket") ]]]]]] )

 

查询：

mixedmysqli::query ( string$query [, int$resultmode = MYSQLI_STORE_RESULT ] )

 

查询结果：

记录条数：$mysqli->num_rows

读取记录：array mysqli_result::fetch_assoc ( void )

 

断开连接：

void mysqli_result::free ( void )

bool mysqli::close ( void )

但是，这并不是必要的，因为脚本执行完毕的时候它们将被自动关闭。

 

插入，更新用的是也是query函数。可以通过$mysqli->affected_rows来获取影响的记录数。

 

<style>td,th{border:1px solid gray;}</style><?phpfunction showBooks(){$db = new mysqli('localhost', 'root', '111111', 'books');$query = "select * from books";if (mysqli_connect_errno()) {echo 'Error: Could not connect to database.  Please try again later.';exit;}$result = $db->query($query);$numResult = $result->num_rows;echo "共".$numResult."条记录<br>";?><table style="border:1px solid gray;" cellspacing="0px"><tr><th>isbn</th><th>作者</th><th>标题</th><th>价格</th></tr><?phpfor($i=0;$i<$numResult;$i++){$row = $result->fetch_assoc();echo "<tr>";echo "<td>".$row['isbn']."</td>";echo "<td>".$row['author']."</td>";echo "<td>".$row['title']."</td>";echo "<td>".$row['price']."</td>";echo "</td>";}$result->free();?></table><?php}function showBooks2(){$db = new mysqli('localhost', 'root', '111111', 'books');$query = "select * from books";if (mysqli_connect_errno()) {echo 'Error: Could not connect to database.  Please try again later.';exit;}$stmt = $db->prepare($query);$stmt->execute();$stmt->bind_result($isbn,$name,$title,$price);$stmt->store_result();$numResult = $stmt->affected_rows;echo "共".$numResult."条记录<br>";?><table style="border:1px solid gray;" cellspacing="0px"><tr><th>isbn</th><th>作者</th><th>标题</th><th>价格</th></tr><?phpwhile($stmt->fetch()){echo "<tr>";echo "<td>".$isbn."</td>";echo "<td>".$name."</td>";echo "<td>".$title."</td>";echo "<td>".$price."</td>";echo "</td>";}$stmt->close();?></table><?php}function insert($isbn,$name,$title,$price){$db = new mysqli('localhost', 'root', '111111', 'books');$query = "insert into books(isbn,author,title,price) values(?,?,?,?)";if (mysqli_connect_errno()) {echo 'Error: Could not connect to database.  Please try again later.';exit;}$stmt = $db->prepare($query);$stmt->bind_param("sssd",$isbn,$name,$title,$price);$stmt->execute();if($stmt->error){echo $stmt->error;exit;}echo "成功插入".$stmt->affected_rows."条数据<br>";$stmt->close();}showBooks();insert("2015-10-09 03号","金庸","天龙八部",86.3);showBooks2();?>