SQL查询中AND条件子句的精确匹配分析与调试

// 示例：使用PDO预处理语句
$command = "SELECT * FROM {$uniluxModel} WHERE gpm = :uniluxGpm AND ewt = :uniluxEwt";
$stmt = $conn->prepare($command);
$stmt->execute([':uniluxGpm' => $uniluxGpm, ':uniluxEwt' => $uniluxEwt]);

SELECT
    *,
    gpm = :uniluxGpm AS gpm_found,
    ewt = :uniluxEwt AS ewt_found
FROM
    {$uniluxModel}
WHERE
    gpm = :uniluxGpm OR ewt = :uniluxEwt;

<?php

// 假设 $conn 已经是一个PDO数据库连接对象
// 假设 $uniluxModel, $uniluxGpm, $uniluxEwt 已经从用户输入获取并经过验证

try {
    // 1. 构建查询字符串：使用OR逻辑，并在SELECT列表中添加匹配标志
    $command = "SELECT *,
                       gpm = :uniluxGpm AS gpm_found,
                       ewt = :uniluxEwt AS ewt_found
                FROM {$uniluxModel}
                WHERE gpm = :uniluxGpm OR ewt = :uniluxEwt";

    // 2. 准备SQL语句
    $stmt = $conn->prepare($command);

    // 3. 绑定参数并执行查询
    $stmt->execute([
        ':uniluxGpm' => $uniluxGpm,
        ':uniluxEwt' => $uniluxEwt
    ]);

    // 4. 获取所有匹配的记录
    $results = $stmt->fetchAll(PDO::FETCH_ASSOC);

    // 5. 分析结果并提供反馈
    if (empty($results)) {
        echo "未找到任何匹配项。";
    } else {
        $gpmMatched = false;
        $ewtMatched = false;

        foreach ($results as $row) {
            if ($row['gpm_found'] == 1) {
                $gpmMatched = true;
            }
            if ($row['ewt_found'] == 1) {
                $ewtMatched = true;
            }

            // 示例：输出每条记录及其匹配状态
            echo "记录ID: " . $row['id'] . ", GPM: " . $row['gpm'] . ", EWT: " . $row['ewt'] . "\n";
            echo "  GPM匹配: " . ($row['gpm_found'] ? '是' : '否') . "\n";
            echo "  EWT匹配: " . ($row['ewt_found'] ? '是' : '否') . "\n";
            echo "-------------------\n";
        }

        // 根据整体匹配情况提供用户反馈
        if ($gpmMatched && $ewtMatched) {
            echo "找到同时满足GPM和EWT条件的记录。\n";
        } elseif ($gpmMatched) {
            echo "未找到同时满足GPM和EWT条件的记录。但找到了GPM匹配的记录。\n";
        } elseif ($ewtMatched) {
            echo "未找到同时满足GPM和EWT条件的记录。但找到了EWT匹配的记录。\n";
        } else {
            // 理论上如果results不为空，至少会有一个匹配，此分支通常不会触发
            echo "找到记录，但未找到与输入GPM或EWT完全匹配的项。\n";
        }
    }

} catch (PDOException $e) {
    echo "数据库查询失败: " . $e->getMessage();
}

?>