PDO rowCount未返回正确数量的受影响的行

Question

我遇到PDO预处理语句和rowCount的问题,返回错误的受影响行数.

我有一个简单的测试数据库:

create table test (
   boolean var1;
);

然后我有以下测试代码:

$sth = $pdo->prepare("INSERT into test (var1) VALUES (:val)");
$sth->execute(array(':val' => true));
echo $sth->rowCount();

哪个按预期返回:受影响的一行

当我插入无效类型并且插入失败时:

$sth = $pdo->prepare("INSERT into test (var1) VALUES (:val)");
$sth->execute(array(':val' => 20));
echo $sth->rowCount();

哪个按预期返回:0行受影响

但是,当我有多个插入 -

$sth = $pdo->prepare("INSERT into test (var1) VALUES (:val)");

$sth->execute(array(':val' => true));
echo $sth->rowCount() . ", ";

$sth->execute(array(':val' => 20));
echo $sth->rowCount();

结果:1,1

如果我翻转执行顺序,我得到:0,1

为什么rowCount() - 在成功语句后的失败语句中未将受影响的行设置为零？

我正在运行php 5.3.6-13和Postgresql 9.1

Answer 1

在我看来，$sth->execute(array(':val' => true))成功完成，从而增加了rowCount，但$sth->execute(array(':val' => 20))没有。这是每个阶段rowCount的状态：$sth

$sth = $pdo->prepare("INSERT into test (var1) VALUES (:val)");  

# No successful DML queries have been done with the $sth yet.
# rowCount == 0

$sth->execute(array(':val' => true));
echo $sth->rowCount() . ", ";

# rowCount increases because of a successful INSERT statement
# rowCount == 1

$sth->execute(array(':val' => 20));
echo $sth->rowCount();

# rowCount does not increase due to failed INSERT statement
# rowCount == 1

现在，让我们以相反的顺序来看一下：

$sth = $pdo->prepare("INSERT into test (var1) VALUES (:val)");  

# No successful DML queries have been done with the $sth yet.
# rowCount == 0

$sth->execute(array(':val' => 20));
echo $sth->rowCount();

# rowCount does not increase due to failed INSERT statement
# rowCount == 0

$sth->execute(array(':val' => true));
echo $sth->rowCount() . ", ";

# rowCount increases because of a successful INSERT statement
# rowCount == 1