从数据库中提取数据并移动并在数组中添加新值
问题描述:
在数据库表中我有Value列。有超过50行。现在在PHP中,我有一个固定的数组10.前10行将从数据库中提取并存储到数组中。当数组将满时,第11个值将尝试插入到数组中,第0个值将移动并且第11个值将插入到数组中。例如像QUEUE过程。从数据库中提取数据并移动并在数组中添加新值
起初它会显示
[[0,17.9999],[1,13.898],...[9,16.98]]
然后[0,17.9999] will move and [10,11.88]
将插入它会打印出如下
[[1,13.898],.......[9,16.98],[10,11.88]]
然后
[2,17.84],......[10,11.88],[11,999]]
等..
如何在php中表示它?
这里是我的代码:
<?php
include("md.php");
$sql = "SELECT * from datatable";
$result =oci_parse($conn, $sql);
$r=oci_execute($result);
$arr = array();
$i=0;
while($row = oci_fetch_array($stid,OCI_ASSOC)){
$arr[] = array_shift(array($i++, (float)$row['VALUE']));
}
echo json_encode($arr);
?>
请帮助。
答
如果你总是在阵列10个按键,尽量
$arr=array_slice($arr,1,9);
$arr[]=$row['VALUE'];
代替
$arr[] = array_shift(array($i++, (float)$row['VALUE']));
注意,这将是正确的,当你已经有阵列10个项目。 见下面
$arr = array(1,2,3,4,5,6,7,8,9,10);
echo json_encode($arr)."<br>";
$con = mysqli_connect('127.0.0.1','app_user2','qwe123','test');
$select="select id from adv where id > 300 and id < 312;";
$res = mysqli_query($con, $select);
while ($row=$res->fetch_assoc()) {
$arr=array_slice($arr,1,9);
$arr[]=$row['id'];
echo json_encode($arr)."<br>";
}
例如在浏览器,它会表现为
[1,2,3,4,5,6,7,8,9,10]
[2,3,4,5,6,7,8,9,10,"301"]
[3,4,5,6,7,8, 9,10,"301","302"]
[4,5,6,7,8,9,10,"301","302","303"]
[5,6,7,8,9,10,"301","302","303","304"]
[6,7,8,9,10,"301","302","303","304","305"]
[7,8,9,10,"301","302","303","304","305","306"]
[8,9,10,"301","302","303","304","305","306","307"]
[9,10,"301","302","303","304","305","306","307","308"]
[10,"301","302","303","304","305","306","307","308","309"]
["301","302","303","304","305","306","307","308","309","310"]
["302","303","304","305","306","307","308","309","310","311"]
答
如果我的理解,对50个条目,你只会得到10,11日被推开数组的第一个值......这就像是最后的10次结局,你不觉得吗?
通过承认你的表有一个自动递增的“ID”字段:
<?php
include("md.php");
// I've changed your SQL query by adding a reverse sort
// on the 'id' field and put a limit of 10 entries
$sql = "SELECT * from datatable ORDER BY id DESC LIMIT 0,10";
$result =oci_parse($conn, $sql);
$r=oci_execute($result);
$arr = array();
$i=0;
while($row = oci_fetch_array($stid, OCI_ASSOC)){
$arr[] = (float)$row['VALUE'];
}
echo json_encode($arr);
?>
我没有测试过这个片段,但它应该很好地工作;)
编辑:请忽略,如果伊利亚的答案就是你想要做的D:
这一切的目的是什么?取最后10条记录? –