我进行了搜索,但找不到任何令人满意的东西
想象一下:
<?php
$connection = new \PDO($dsn, $user, $pass);
$stmt1 = $connection->prepare("
SELECT
*
FROM
table
WHERE
a = :a
AND b = :b
AND c = :c
AND d = :d
AND search LIKE :search
");
$stmt1->bindValue(":a", $a);
$stmt1->bindValue(":b", $b);
$stmt1->bindValue(":c", $c);
$stmt1->bindValue(":d", $d);
$stmt2 = clone $stmt1;
$stmt1->bindValue(":search", "a%");
$stmt2->bindValue(":search", "b%");
$stmt1->execute();
$stmt2->execute();
while(($r1 = $stmt1->fetchObject()) && ($r2 = $stmt2->fetchObject()))
echo $r1->foo . " " . $r2->foo . "\n";
}
我可以做这样的事情吗?我如何克隆
/重用一个PDOStatement
实例并在使用它的同时使用它的原始实例?
不要说“使用UNION
”,这不是我问题的重点:P
提前谢谢你。
最佳答案
这不是准备好的语句重用的目的。重用准备好的语句的想法是连续,而不是并发。
所以你可以这样做:
$connection = new \PDO($dsn, $user, $pass);
$stmt = $connection->prepare("
SELECT *
FROM table
WHERE a = :a
AND b = :b
AND c = :c
AND d = :d
AND search LIKE :search
");
$stmt->bindValue(":a", $a);
$stmt->bindValue(":b", $b);
$stmt->bindValue(":c", $c);
$stmt->bindValue(":d", $d);
foreach (["a%", "b%"] as $search) {
$stmt->bindValue(":search", $search);
$stmt->execute();
while($r = $stmt->fetchObject()) {
echo $r->foo . "\n";
}
$stmt->closeCursor();
}
如果您想同时处理多个结果集(至少使用 MySQL),您需要执行以下操作之一:
- 使用一组适当的
UNION
/JOIN
创建单个结果集。 - 将结果集缓存在内存中,并在所有数据可用时再次迭代它们。
- 创建多个连接 - 每个连接不能有多个打开的语句游标,但可以有多个打开的连接。
如果你想使用多个连接,你的代码变成:
$query = "
SELECT *
FROM table
WHERE a = :a
AND b = :b
AND c = :c
AND d = :d
AND search LIKE :search
";
$connection1 = new \PDO($dsn, $user, $pass);
$connection2 = new \PDO($dsn, $user, $pass);
$stmt1 = $connection1->prepare($query);
$stmt1->bindValue(":a", $a);
$stmt1->bindValue(":b", $b);
$stmt1->bindValue(":c", $c);
$stmt1->bindValue(":d", $d);
$stmt1->bindValue(":search", "a%");
$stmt2 = $connection2->prepare($query);
$stmt2->bindValue(":a", $a);
$stmt2->bindValue(":b", $b);
$stmt2->bindValue(":c", $c);
$stmt2->bindValue(":d", $d);
$stmt2->bindValue(":search", "b%");
$stmt1->execute();
$stmt2->execute();
while(($r1 = $stmt1->fetchObject()) && ($r2 = $stmt2->fetchObject()))
echo $r1->foo . " " . $r2->foo . "\n";
}
$stmt1->closeCursor();
$stmt2->closeCursor();
关于php - 如何重用 PDOStatement prepare?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/21305224/