简单使用PDO

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首先基本配置：

连接MYSQL

<?php

$dsn = 'mysql:host=localhost;dbname=world;';

$user = 'user';

$password = 'secret';

try

{

$dbh = new PDO($dsn, $user, $password);

}

catch (PDOException $e)

{

echo 'Connection failed: ' . $e->getMessage();

}

?>

连接SQLite

<?php

$dsn = 'sqlite2:"C:\sqlite\world.db"';

try

{

$dbh = new PDO($dsn);

}

catch (PDOException $e)

{

echo 'Connection failed: ' . $e->getMessage();

}

?>

连接PostgreSQL

<?php

$dsn = 'pgsql:host=localhost port=5432 dbname=world user=user ';

$dsn .= 'password=secret';

try

{

$dbh = new PDO($dsn);

}

catch (PDOException $e)

{

echo 'Connection failed: ' . $e->getMessage();

}

?>

端口：MySQL是 3306, PostgreSQL是 5432

第一步：怎样从数据库中获取数据

用query：

$country = 'USA';

try

{

$dbh = new PDO($dsn, $user, $password);

$dbh->setAttribute(PDO::ATTR_ERRMODE,

PDO::ERRMODE_EXCEPTION);

$sql = 'Select * from city where CountryCode =' .

$dbh->quote($country);

foreach (

$dbh->query($sql)

as $row)

{

print $row['Name'] . "\t";

print $row['CountryCode'] . "\t";

print $row['Population'] . "\n";

}

}

catch (PDOException $e)

{

echo 'PDO Exception Caught.

';

echo 'Error with the database: <br />';

echo 'SQL Query: ', $sql;

echo 'Error: ' . $e->getMessage();

用Perpare和Execute

$country = 'USA';

try

{

$dbh = new PDO($dsn, $user, $password);

$sql = 'Select * from city where CountryCode =:country';

$dbh->setAttribute(PDO::ATTR_ERRMODE,

PDO::ERRMODE_EXCEPTION);

$stmt =

$dbh->prepare($sql)

;

$stmt->bindParam(':country', $country, PDO::PARAM_STR);

$stmt->execute();

while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {

print $row['Name'] . "\t";

print $row['CountryCode'] . "\t";

print $row['Population'] . "\n";

}

}

catch (PDOException $e)

{

echo 'PDO Exception Caught. ';

echo 'Error with the database: <br />';

echo 'SQL Query: ', $sql;

echo 'Error: ' . $e->getMessage();

}

}

query、fecht和execute的比较：

query对只查询一次是比较有利的，多次查询用fetch和execute

fetch的选择内容：

假如想用面向对象的代码，可以使用fetchObject方法，顾名思义将返回对象，例如：

while ($row =$stmt->fetchObject())

{

print $row->Name . "\t";

print $row->CountryCode . "\t";

print $row->Population . "\n";

}

基本的pdo的操作就这些。

转载于:https://my.oschina.net/chen08054/blog/17308