Question

我正在使用此PDO查询从MySQL调用数据。

$sql = "SELECT itemName FROM furniture WHERE itemID = :item";

在调用此特定itemName时，是否可以通过在同一查询中使用其itemID来获取下一个和上一个itemNames，而无需编写新查询来获取下一个和上一个itemNames？

e.g。如果

itemID   |   itemName
___________________________
553      |   Mahogani Black Chair
554      |   Teak Round Table
555      |   Thulang Relaxing Chair
556      |   Teak Relaxing Chair

$sql = "SELECT itemName FROM furniture WHERE itemID = :item";
$stmt = $connect->prepare($sql);
$stmt->execute(array(':item'=>"554"));
$rslt = $stmt->fetchAll(PDO::FETCH_ASSOC);

我正在考虑获取Teak Round Table和Mahogani Black Chair以及Thulang Relaxing Chair

Answer 1

请使用此代码：

(SELECT itemName FROM furniture WHERE itemID < 554 order by itemID desc limit 1) 
UNION
(SELECT itemName FROM furniture WHERE itemID >= 554 order by itemID asc limit 2)

示例代码：

MyTable:
================
id  Store_name
================
1   English
2   French
3   Tamil
4   Uk
5   US

<?php  
$con = mysqli_connect("localhost","root","ramki","ramki");
$sql = "(SELECT store_name FROM store WHERE id < 2 order by id desc limit 1) 
        UNION
        (SELECT store_name FROM store WHERE id >= 2 order by id asc limit 2)";
$query = mysqli_query($con,$sql);
while ($row = mysqli_fetch_assoc($query)) {
echo $row['store_name'];
echo "<br>";
}
?>

Answer 2

$sql = "SELECT itemName FROM furniture WHERE itemID IN (:item-1, :item, :item+1) ORDER BY itemID";

为了迭代结果，您还可以使用PDO fetch() function来获取每一行。

获取同一查询中的下一条和上一条记录

2 个答案: