2.PDO的使用

1. exec()

1.1 建表
phptry {$dsn &＃61; &＃39;mysql:host&＃61;localhost;dbname&＃61;test&＃39;;$username &＃61; &＃39;root&＃39;;$password &＃61; &＃39;123456&＃39;;$pdo &＃61; new PDO($dsn,$username,$password);//exec();执行一条 sql 语句&＃xff0c;并返回受影响的记录的条数,如果没有受影响返回0//exec 对 select 没有作用$sql &＃61; <<<EOF
create table if not exists user(id int unsigned auto_increment key,username varchar(20) not null unique,password char(32) not null,email varchar(32) not null
)
EOF;$res &＃61; $pdo->exec($sql);var_dump($res);} catch (PDOException $e) {echo $e->getMessage();
}返回 0&＃xff1b;

插入记录&＃xff1a;
//插入一条记录//$sql &＃61; &＃39;insert user(username,password,email) values("wjh",md5("wjh"),"188&＃64;qq.com")&＃39;;//$res &＃61; $pdo->exec($sql); 返回 1//插入多条记录
$sql &＃61; <<values("wjh1",md5("wjh"),"188&＃64;qq.com"),("wjh2",md5("wjh"),"188&＃64;qq.com"),("wjh3",md5("wjh"),"188&＃64;qq.com")
EOF;$res &＃61; $pdo->exec($sql); // 返回 3$pdo->lastInsertId(); //返回 最后一条插入记录的 ID

更新记录&＃xff1a;$sql &＃61; &＃39;update user set username&＃61;"immoc" where id&＃61;3&＃39;;$res &＃61; $pdo->exec($sql);

删除记录$sql &＃61; &＃39;delete from user where id&＃61;2&＃39;;$res &＃61; $pdo->exec($sql);

获取错误信息&＃xff1a;//删除记录$sql &＃61; &＃39;delete from user12 where id&＃61;2&＃39;;$res &＃61; $pdo->exec($sql);if ($res &＃61;&＃61;&＃61; false) {//返回数据库句柄上一次操作相关的SQLSTATE的值echo $pdo->errorCode();echo &＃39;
&＃39;;//返回数据库句柄上一次操作错误信息的数组&＃xff0c;数组包括3个单元//1. 0 &＃61;> SQLSTATE//2. 1 &＃61;> 错误编号,CODE//3. 3 &＃61;> 信息$errInfo &＃61; $pdo->errorInfo();var_dump($errInfo);} else {var_dump($res);}

2. query()

try {$pdo &＃61; new PDO(&＃39;mysql:host&＃61;localhost;dbname&＃61;test&＃39;,&＃39;root&＃39;,&＃39;123456&＃39;);//$sql &＃61; &＃39;select * from user where id&＃61;2;&＃39;;$sql &＃61; &＃39;select * from user;&＃39;;//执行 sql 语句&＃xff0c;返回PDOStatement对象$stmt &＃61; $pdo->query($sql);foreach ($stmt as $row) {echo $row[&＃39;id&＃39;];echo &＃39;
&＃39;;echo $row[&＃39;username&＃39;];echo &＃39;
&＃39;;echo $row[&＃39;password&＃39;];echo &＃39;
&＃39;;echo $row[&＃39;email&＃39;];echo &＃39;
&＃39;;}} catch (PDOException $e) {echo $e->getMessage();
}

3.prepare() and execute()

try {$pdo &＃61; new PDO(&＃39;mysql:host&＃61;localhost;dbname&＃61;test&＃39;,&＃39;root&＃39;,&＃39;123456&＃39;);$sql &＃61; "select * from user";//返回一个 PDOStatement 对象//prepare($sql);准备 sql 语句$stmt &＃61; $pdo->prepare($sql);//设置默认的返回模式$stmt->setFetchMode(PDO::FETCH_OBJ);// execute(); 执行预处理语句,返回布尔值$res &＃61; $stmt->execute();//取出结果集取出一条记录
// $row &＃61; $stmt->fetch();if ($res) {while($row &＃61; $stmt->fetch(PDO::FETCH_ASSOC)) {var_dump($row );}}//用 fetchAll()/*$rows &＃61; $stmt->fetchAll();var_dump($rows);*/} catch (PDOException $e) {echo $e->getMessage();
}

4.getAttribute() and setAttribute()

try {$dsn &＃61; &＃39;mysql:host&＃61;localhost;dbname&＃61;test&＃39;;$username &＃61; &＃39;root&＃39;;$password &＃61; &＃39;123456&＃39;;$pdo &＃61; new PDO($dsn,$username,$password);// 默认为 1 &＃xff0c;自动提交echo &＃39;自动提交 : &＃39; . $pdo->getAttribute(PDO::ATTR_AUTOCOMMIT);echo &＃39;
&＃39;;echo &＃39;默认错误处理模式 &＃xff1a;&＃39; . $pdo->getAttribute(PDO::ATTR_ERRMODE);echo &＃39;
&＃39;;$pdo->setAttribute(PDO::ATTR_AUTOCOMMIT,0);echo &＃39;自动提交 : &＃39; . $pdo->getAttribute(PDO::ATTR_AUTOCOMMIT);
} catch (PDOException $e) {echo $e->getMessage();
}

try {$dsn &＃61; &＃39;mysql:host&＃61;localhost;dbname&＃61;test&＃39;;$username &＃61; &＃39;root&＃39;;$password &＃61; &＃39;123456&＃39;;$pdo &＃61; new PDO($dsn,$username,$password);$attArr &＃61; array(&＃39;AUTOCOMMIT&＃39;,&＃39;CASE&＃39;,&＃39;CLIENT_VERSION&＃39;,&＃39;CONNECTION_STATUS&＃39;,&＃39;DRIVER_NAME&＃39;,&＃39;ERRMODE&＃39;,&＃39;ORACLE_NULLS&＃39;,&＃39;PERSISTENT&＃39;,&＃39;PREFETCH&＃39;,&＃39;SERVER_INFO&＃39;,&＃39;SERVER_VERSION&＃39;,&＃39;TIMEOUT&＃39;);foreach ($attArr as $attr) {echo "PDO_ATTR_$attr : ";echo $pdo->getAttribute(constant("PDO::ATTR_$attr"));echo &＃39;
&＃39;;}} catch (PDOException $e) {echo $e->getMessage();
}