PHP连接MySql.doc

PHP连接MySQL使用PHP访问MySQL访问前要先过滤用户输入的字符串.用到的函数:trim()get_magic_quotes_gpc()addslashes()stripslashes()htmlspecialchars() - 将HTML特定的符号进行转换$new = htmlspecialchars(Test, ENT_QUOTES);echo $new; / 输出为:<a href=test>Test</a>连接MySQL构造mysqli类,这时可以通过调用对象的方法(类似于$db-close() )来查询$mysqli= new mysqli(localhost, my_user, my_password, my_db, 8000);/$ mysqli是一个对象/mysqli是一个类,构造函数的参数依次为 : 主机,用户,密码,数据库,端口,Socket号一般来说要加止抑制错误符号 $ mysqli = new mysqli(localhost, my_user, my_password, my_db, 8000);/连接是否成功可以通过函数来判断亦可以使用过程方法,这时要查询就要使用类似于mysqli_close($link) 的方式了$link= mysqli_connect (localhost, my_user, my_password, my_db, 8000);/$link是一个资源检测是否连接成功:if (!$mysqli) /连接时使用 抑制错误,此时再判断退出(或继续) die(Connect Error: . mysqli_connect_errno();/die相当于exit()函数或者if (mysqli_connect_errno()/不论是对象连接还是过程连接，都可以用此函数返回一个连接错误值echo ”Error! ”;选择数据库$mysqli-select_db(world);/相当于SQL语句use dbname;或mysqli_select_db($link, world);查询数据库$result = $mysqli-query(CREATE TEMPORARY TABLE myCity LIKE City);/或者是：$mysqli-query($query) 参数可以是变量或$result = mysqli_query($link, SELECT * FROM City, MYSQLI_USE_RESULT);发送给MySQL的查询不需要在末尾加分号检索查询结果返回结果的行数（记录数）$row_cnt = $result-num_rows;或$row_cnt = mysqli_num_rows($result);返回行（记录）n fetch_assoc -以相关数组返回；以key=value的形式while ($row = $result-fetch_assoc() /返回一条记录，当没有记录时返回NULL printf (%s (%s)n, $rowName, $rowCountryCode);/打印结果 或$row = mysqli_fetch_assoc($result);一般的在遍历记录前，要先进行整理echo stripslashes($rowName);/把多余的 删除while ($row = $result-fetch_row() printf (%s (%s)n, $row0, $row1); n fetch_row - 以枚举形式返回，类似于 $row0,$rou1的形式while ($row = mysqli_fetch_row($result) printf (%s (%s)n, $row0, $row1);n fetch_object - 将一行取回到一个对象中；访问时通过 $obj-name , $obj-Address 来实现while ($obj = $result-fetch_object() printf (%s (%s)n, $obj-Name, $obj-Address);n MySQLi_result类的属性、函数说明：mysqli_result-current_field Get current field offset of a result pointermysqli_result:data_seek Adjusts the result pointer to an arbitary row in the resultmysqli_result:fetch_all Fetches all result rows as an associative array, a numeric array, or bothmysqli_result:fetch_array Fetch a result row as an associative, a numeric array, or bothmysqli_result:fetch_assoc Fetch a result row as an associative array(以相关数组返回；即以key=value的形式)mysqli_result:fetch_field_direct Fetch meta-data for a single fieldmysqli_result:fetch_field Returns the next field in the result setmysqli_result:fetch_fields Returns an array of objects representing the fields in a result setmysqli_result:fetch_object Returns the current row of a result set as an object(返回对象；访问时通过 $obj-name , $obj-Address 来实现)mysqli_result:fetch_row Get a result row as an enumerated arraymysqli_result-field_count Get the number of fields in a resultmysqli_result:field_seek Set result pointer to a specified field offsetmysqli_result:free Frees the memory associated with a resultmysqli_result-lengths Returns the lengths of the columns of the current row in the result setmysqli_result-num_rows Gets the number of rows in a result*相关数组即索引数组，即数组的元素以: key=value 的形式存储从数据库断开：先释放结果，再断开数据库$result-free();$mysqli-close();或mysqli_free_result ($result );/注意，释放结果的过程函数只有这一个mysqli_close ( $link );严格来说，当一个脚本执行完毕，数据库会被自动释放。将新信息存入数据库n affected_rows (mysqli_affected_rows) - 返回操作的行数；通常在INSERT、UPDATE、DELETE中使用此函数，而在SELECT语句中使用num_rows函数来得到行数if (!get_magic_quotes_gpc()/存入数据前确保数据库的安全性$isbn = addslashes($isbn);$author = addslashes($author);$title = addslashes($title);$price = doubleval($price); $query = in