PHP:准备好的语句，需要 IF 语句帮助

Question

我有以下代码:

$sql = "SELECT name, address, city FROM tableA, tableB WHERE tableA.id = tableB.id";

if (isset($price) ) {
    $sql = $sql . ' AND price = :price ';
}
if (isset($sqft) ) {
    $sql = $sql . ' AND sqft >= :sqft ';
}
if (isset($bedrooms) ) {
    $sql = $sql . ' AND bedrooms >= :bedrooms ';
}


$stmt = $dbh->prepare($sql);


if (isset($price) ) {
    $stmt->bindParam(':price', $price);
}
if (isset($sqft) ) {
    $stmt->bindParam(':price', $price);
}
if (isset($bedrooms) ) {
    $stmt->bindParam(':bedrooms', $bedrooms);
}


$stmt->execute();
$result_set = $stmt->fetchAll(PDO::FETCH_ASSOC);

我注意到的是我拥有的冗余的多个 IF 语句。

问题 : 有什么办法可以清理我的代码，这样我就没有这些准备好的语句的多个 IF 语句吗？

Answer 1

这与用户 asked 的问题非常相似。我最近在我的书 SQL Antipatterns 的论坛。我给了他类似的答案:

$sql = "SELECT name, address, city FROM tableA JOIN tableB ON tableA.id = tableB.id";

$params = array();
$where = array();

if (isset($price) ) {
    $where[] = '(price = :price)';
    $params[':price'] = $price;
}
if (isset($sqft) ) {
    $where[] = '(sqft >= :sqft)';
    $params[':sqft'] = $sqft;
}
if (isset($bedrooms) ) {
    $where[] = '(bedrooms >= :bedrooms)';
    $params[':bedrooms'] = $bedrooms;
}

if ($where) {
  $sql .= ' WHERE ' . implode(' AND ', $where);
}

$stmt = $dbh->prepare($sql);

$stmt->execute($params);
$result_set = $stmt->fetchAll(PDO::FETCH_ASSOC);