标签:datatables mysql php pdo
众所周知,PHP v7.0中已删除了Mysql,我正在尝试使用pdo使用以下示例通过数据表获取数据(服务器端)(但在mysql中需要使用pdo):
码:
列:
/* Array of database columns which should be read and sent back to DataTables. Use a space where
* you want to insert a non-database field (for example a counter or static image)
*/
$aColumns = array( 'first_name', 'last_name', 'position', 'office', 'salary' );
/* Indexed column (used for fast and accurate table cardinality) */
$sIndexColumn = "id";
/* DB table to use */
$sTable = "datatables_demo";
创建PDO连接:
$db_host = "localhost";
$db_name = "sadad";
$db_user = "root";
$db_pass = "root";
try{
$db_con = new PDO("mysql:host={$db_host};dbname={$db_name}",$db_user,$db_pass);
$db_con->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
}
catch(PDOException $e){
echo $e->getMessage();
}
以下代码:
$sLimit = "";
if ( isset( $_GET['iDisplayStart'] ) && $_GET['iDisplayLength'] != '-1' )
{
$sLimit = "LIMIT ".$db_con->quote( $_GET['iDisplayStart'] ).", ".
$db_con->quote( $_GET['iDisplayLength'] );
}
/*
* Ordering
*/
if ( isset( $_GET['iSortCol_0'] ) )
{
$sOrder = "ORDER BY ";
for ( $i=0 ; $i<intval( $_GET['iSortingCols'] ) ; $i++ )
{
if ( $_GET[ 'bSortable_'.intval($_GET['iSortCol_'.$i]) ] == "true" )
{
$sOrder .= $aColumns[ intval( $_GET['iSortCol_'.$i] ) ]."
".$db_con->quote( $_GET['sSortDir_'.$i] ) .", ";
}
}
$sOrder = substr_replace( $sOrder, "", -2 );
if ( $sOrder == "ORDER BY" )
{
$sOrder = "";
}
}
/*
* Filtering
* NOTE this does not match the built-in DataTables filtering which does it
* word by word on any field. It's possible to do here, but concerned about efficiency
* on very large tables, and MySQL's regex functionality is very limited
*/
$sWhere = "";
if ( $_GET['sSearch'] != "" )
{
$sWhere = "WHERE (";
for ( $i=0 ; $i<count($aColumns) ; $i++ )
{
$sWhere .= $aColumns[$i]." LIKE '%".$db_con->quote( $_GET['sSearch'] )."%' OR ";
}
$sWhere = substr_replace( $sWhere, "", -3 );
$sWhere .= ')';
}
/* Individual column filtering */
for ( $i=0 ; $i<count($aColumns) ; $i++ )
{
if ( $_GET['bSearchable_'.$i] == "true" && $_GET['sSearch_'.$i] != '' )
{
if ( $sWhere == "" )
{
$sWhere = "WHERE ";
}
else
{
$sWhere .= " AND ";
}
$sWhere .= $aColumns[$i]." LIKE '%".$db_con->quote($_GET['sSearch_'.$i])."%' ";
}
}
$my = str_replace(" , ", " ", implode(", ", $aColumns));
/*
* SQL queries
* Get data to display
*/
$sQuery = $db_con->query("SELECT {$my} FROM {$sTable} {$sWhere} {$sOrder} {$sLimit}")->fetchAll();
//$rResult = ( $sQuery );
/* Data set length after filtering */
$sQuery = "
SELECT FOUND_ROWS()
";
//$rResultFilterTotal = $sQuery;
$aResultFilterTotal = $sQuery;
$iFilteredTotal = $aResultFilterTotal[0];
/* Total data set length */
$sQuery = "
SELECT COUNT(".$sIndexColumn.")
FROM $sTable
";
$rResultTotal = $db_con->query( $sQuery ) or die(mysql_error());
$aResultTotal = $rResultTotal->fetchAll();
$iTotal = $aResultTotal[0];
/*
* Output
*/
$output = array(
"sEcho" => intval($_GET['sEcho']),
"iTotalRecords" => $iTotal,
"iTotalDisplayRecords" => $iFilteredTotal,
"aaData" => array()
);
while ( $aRow = $rResult->fetchAll() )
{
$row = array();
for ( $i=0 ; $i<count($aColumns) ; $i++ )
{
if ( $aColumns[$i] == "version" )
{
/* Special output formatting for 'version' column */
$row[] = ($aRow[ $aColumns[$i] ]=="0") ? '-' : $aRow[ $aColumns[$i] ];
}
else if ( $aColumns[$i] != ' ' )
{
/* General output */
$row[] = $aRow[ $aColumns[$i] ];
}
}
$output['aaData'][] = $row;
}
echo json_encode( $output );
错误:
但是我遇到了错误,我不知道上面要更改什么,请开始使用pdo,请使用代码更新答案:
更新了代码,现在收到以下错误
[28-Aug-2018 16:58:39 UTC] PHP Fatal error: Uncaught exception 'PDOException' with message 'SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ''asc' LIMIT '0', '50'' at line 2' in C:\MAMP\htdocs\backend\my.php:131
Stack trace:
#0 C:\MAMP\htdocs\backend\my.php(131): PDO->query('SELECT first_na...')
#1 {main}
thrown in C:\MAMP\htdocs\backend\my.php on line 131
**ERROR:**
解决方法:
我在这里看到一个问题:
$sWhere .= $aColumns[$i]." LIKE '%".$db_con->quote($_GET['sSearch_'.$i])."%' ";
PDO :: quote()函数的输出与旧的mysql_real_escape_string()函数不同.
假设您的字符串是“ O’Reilly”,并且您需要转义撇号字符.
mysql_real_escape_string(“ O’Reilly”)将返回:
O\'Reilly
而$db_con-" quote(“ O’Reilly”)将返回:
'O\'Reilly'
quote()函数将字符串定界符添加到字符串的开头和结尾.这使其与MySQL内置函数QUOTE()相同
因此,当您使用PDO :: quote()的方式时:
$sWhere .= $aColumns[$i]." LIKE '%".$db_con->quote($_GET['sSearch_'.$i])."%' ";
产生的SQL子句如下所示:
... WHERE mycolumn LIKE '%'search'%' ...
这是行不通的.您需要它是:
... WHERE mycolumn LIKE '%search%' ...
一种解决方案是添加%通配符,然后引用结果:
$sWhere .= $aColumns[$i]." LIKE ".$db_con->quote('%'.$_GET['sSearch_'.$i].'%') ;
现在,它利用PDO :: quote()添加字符串定界符.
顺便说一下,我找到了所有.字符串连接使PHP看起来很糟糕.很难编写代码,也很难阅读和调试代码.我更喜欢直接在字符串内部使用变量.并且不要害怕用两行代码来完成这项工作.对于代码可读性而言,将太多内容填入一行并不总是最好的.
$pattern = $db_con->quote("%{$_GET["sSearch_$i"]}%");
$sWhere .= "{$aColumns[$i]} LIKE {$pattern}";
但是还有另一种更容易,更安全的方式.
使用查询参数代替转义/引用.
$params[] = "%{$_GET["sSearch_$i"]}%";
$sWhere .= "{$aColumns[$i]} LIKE ?";
后来…
$stmt = $db_con->prepare($sQuery);
$stmt->execute($params);
while ($row = $stmt->fetchAll()) {
...
}
使用参数比使用转义/引用更简单.您不必费神去问报价是否正确平衡,因为参数占位符?不需要字符串定界符.
如果您正在学习PDO,建议您阅读以下内容:
> https://phpdelusions.net/pdo-一个很好的教程.
> http://php.net/pdo-参考文档.
两者都是重要和有用的.参考文档并不适合学习,但是在您学习本教程之后,它们对您有用,以提醒您自己语法,参数,返回值等.我已经做了很多PDO编码,但是我经常打开参考文档.
标签:datatables,mysql,php,pdo 来源: https://codeday.me/bug/20191108/2009160.html
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