我实际上是PDO的新手
这里我试图从mysql中获取数据并以xml显示。
我使用mysql完成了它,但我无法使用PDO完成它。
这是我的PHP代码
<?php
error_reporting(E_ALL);
$host = "localhost";
$user = "root";
$pass = "root";
$database = "my_db";
// replace by a real *.xsl file, e.g.
// $xslt_file = "exam.xsl";
$xslt_file = FALSE;
// If true, will output XML without XSLT
$raw = TRUE;
$SQL_query = "SELECT * FROM `battery` order by waste asc";
$DB_link = mysql_connect($host, $user, $pass) or die("Could not connect to host.");
mysql_select_db($database, $DB_link) or die ("Could not find or access the database.");
$result = mysql_query ($SQL_query, $DB_link) or die ("Data not found. Your SQL query didn't work... ");
$left = "<";
$right = ">";
if ($xslt_file or $raw) {
// we produce XML
header("Content-type: text/xml");
$XML = "<?xml version=\"1.0\"?>\n";
if (!$raw) $XML .= "<?xml-stylesheet href=\"$xslt_file\" type=\"text/xsl\" ?>";
}
else {
// we produce HTML. All XML tags are replaced by printable entities
$XML = "Don't forget to create an XSLT file .... <p>";
$XML .= "<pre>\n";
$left = "<";
$right = ">";
}
// root node
$XML .= $left . "result" . $right . "\n";
// rows
while ($row = mysql_fetch_array($result, MYSQL_ASSOC)) {
$XML .= "\t" . $left. "row" . $right . "\n"; // creates either "<row>" or "<row>"
$i = 0;
// cells
foreach ($row as $cell) {
// Escaping illegal characters
$cell = str_replace("&", "&", $cell);
$cell = str_replace("<", "<", $cell);
$cell = str_replace(">", ">", $cell);
$cell = str_replace("\"", """, $cell);
$col_name = mysql_field_name($result,$i);
// creates the "<tag>contents</tag>" representing the column, either as XML or for display in HTML
$XML .= "\t\t" . $left . $col_name . $right . $cell . $left . "/" . $col_name . $right ."\n";
$i++;
}
$XML .= "\t" . $left. "/row" . $right . "\n";
}
$XML .= $left . "/result" . $right . "\n";
echo $XML;
if (!$xslt_file && !$raw) echo "</pre>";
?>
我正在尝试很多,但我无法使用PDO完成它 我需要一些帮助。 任何帮助将不胜感激。
我试过的我的PDO代码是
<?php
$dbtype = "mysql";
$dbhost = "localhost";
$dbname = "my_db";
$dbuser = "root";
$dbpass = "root";
$conn = new PDO("mysql:host=$dbhost;dbname=$dbname",$dbuser,$dbpass);
$xslt_file = FALSE;
$raw = TRUE;
$SQL_query = "SELECT * FROM `battery` order by waste asc";
$result = $conn->query($SQL_query);
$left = "<";
$right = ">";
if ($xslt_file or $raw) {
header("Content-type: text/xml");
$XML = "<?xml version=\"1.0\"?>\n";
if (!$raw) $XML .= "<?xml-stylesheet href=\"$xslt_file\" type=\"text/xsl\" ?>";
}
else {
$XML = "Don't forget to create an XSLT file .... <p>";
$XML .= "<pre>\n";
$left = "<";
$right = ">";
}
$XML .= $left . "result" . $right . "\n";
while($row = $result->fetch(PDO::FETCH_ASSOC)) {
$XML .= "\t" . $left. "row" . $right . "\n"; // creates either "<row>" or "<row>"
$i = 0;
// cells
foreach ($row as $cell) {
// Escaping illegal characters
$cell = str_replace("&", "&", $cell);
$cell = str_replace("<", "<", $cell);
$cell = str_replace(">", ">", $cell);
$cell = str_replace("\"", """, $cell);
$col_name = $result->fetchAll(PDO::FETCH_COLUMN);
// creates the "<tag>contents</tag>" representing the column, either as XML or for display in HTML
$XML .= "\t\t" . $left . $col_name . $right . $cell . $left . "/" . $col_name . $right ."\n";
$i++;
}
$XML .= "\t" . $left. "/row" . $right . "\n";
}
$XML .= $left . "/result" . $right . "\n";
echo $XML;
if (!$xslt_file && !$raw) echo "</pre>";
?>
但它没有显示任何内容
答案 0 :(得分:0)
获取列名称的正确方法是
$q = $dbh->prepare("DESCRIBE tablename");
$q->execute();
$table_fields = $q->fetchAll(PDO::FETCH_COLUMN);
然而,当您提取一个关联时,您可以将foreach循环更改为:
foreach ($row as $col_name => $cell) {
可能还有其他问题,您是否尝试在每个PDO函数调用的结果上使用print_r来检查它在哪个位置失败?
答案 1 :(得分:0)
你连接到这样的数据库:
$dbhost = "localhost";
$dbname = "testcreate";
$dbuser = "root";
$dbpass = "mysql";
try {
$db = new PDO('mysql:host='.$dbhost.';dbname='.$dbname.';charset=utf-8', ''.$dbuser.'', ''.$dbpass.'');
$db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
} catch (PDOException $e) {
echo 'Error : <br>' . $e->getMessage();
}
PS:你不需要尝试和捕获,但我们过去常常得到错误并以一种很好的方式处理它
接下来我们这样查询:
$db->query(SELECT * FROM node WHERE node_name='$nodename'");
我们这样取得:
$query = $db->query(SELECT * FROM node WHERE node_name='$nodename'");
$row = $query->fetch(PDO::FETCH_OBJ);
现在您使用$row->name
作为示例
这里有更多关于PDO :: FETCH
的信息
PDO :: FETCH_ASSOC :返回按结果集中返回的列名索引的数组
PDO :: FETCH_BOTH (默认值):返回由结果集中返回的列名和0索引列号索引的数组
PDO :: FETCH_BOUND :返回TRUE,并将结果集中列的值分配给它们所属的PHP变量 与PDOStatement :: bindColumn()方法绑定
PDO :: FETCH_CLASS :返回所请求类的新实例,将结果集的列映射到中的命名属性 类。如果fetch_style包含PDO :: FETCH_CLASSTYPE(例如, PDO :: FETCH_CLASS | PDO :: FETCH_CLASSTYPE)然后是班级的名称 由第一列的值确定。
PDO :: FETCH_INTO :更新请求类的现有实例,将结果集的列映射到中的命名属性 班级
PDO :: FETCH_LAZY :组合PDO :: FETCH_BOTH和PDO :: FETCH_OBJ,在访问时创建对象变量名称
PDO :: FETCH_NUM :返回按结果集中返回的列号索引的数组,从第0列开始
PDO :: FETCH_OBJ :返回一个匿名对象,其属性名与结果集中返回的列名相对应