php - MYSQL 使用 AND 和 OR 从数据库中选择数据

Question

我想从此表中选择 * 数据，以便根据我选择的过滤器显示所有内容。

我的 table :

tbl_预订

res_id | trans_code |   status | order_type   |    type_of_order  | date_ordered
------ | -----------|----------|--------------|-------------------|-------------
  1    |   111-111  |Delivered | For Delivery | Online Transaction|2016-10-09
------ | -----------|----------|--------------|-------------------|-------------
  2    |   111-112  |Delivered | For Pick-up  | Online Transaction|2016-10-09
------ | -----------|----------|--------------|-------------------|-------------
  3    |   111-113  |Cancelled | For Delivery | Online Transaction|2016-10-09
------ | -----------|----------|--------------|-------------------|-------------
  4    |   111-114  |          | For Purchase | Online Transaction|2016-10-09
------ | -----------|----------|--------------|-------------------|-------------
  5    |   111-115  |          | For Pick-up  | Walkin Transaction|2016-10-09
------ | -----------|----------|--------------|-------------------|-------------
  6    |   111-116  |          | For Purchase | Walkin Transaction|2016-10-09
------ | -----------|----------|--------------|-------------------|-------------
  7    |   111-117  |Delivered | For Pick-up  | Walin Transaction |2016-10-09
------ | -----------|----------|--------------|-------------------|-------------
  8    |   111-118  |Delivered | For Delivery | Online Transaction|2016-10-08
------ | -----------|----------|--------------|-------------------|-------------
  9    |   111-119  |Delivered | For Pick-up  | Online Transaction|2016-10-08
------ | -----------|----------|--------------|-------------------|-------------
 10    |   111-110  |Cancelled | For Delivery | Online Transaction|2016-10-08
------ | -----------|----------|--------------|-------------------|-------------
 11    |   111-100  |          | For Purchase | Online Transaction|2016-10-08
------ | -----------|----------|--------------|-------------------|-------------
 12    |   111-101  |          | For Pick-up  | Walkin Transaction|2016-10-08
------ | -----------|----------|--------------|-------------------|-------------
 13    |   111-102  |          | For Purchase | Walkin Transaction|2016-10-08
------ | -----------|----------|--------------|-------------------|-------------
 14    |   111-103  |Delivered | For Pick-up  | Walin Transaction |2016-10-08

我的表格:

<form method="post" action="">
<select name="filter">
<option value="Today">Filter Data for today</option>
<option value="Yesterday">Filter Data for yesterday</option>
</select>
<input type="submit" value="Filter"/>
</form>

我的 PHP 代码以及获取过滤器的示例查询

<?php
//inclue db connection

if(isset($_POST["filter"])){
$get_filter = $_POST["filter"];
if($filter == "Today"){
  $sql = mysql_query("SELECT * FROM tbl_reservation WHERE status = 'Delivered' OR status = 'Cancelled' OR status = '' AND DATE(date_ordered) = DATE(now()) ");
}elseif($filter == "Yesterday"){
  $sql = mysql_query("SELECT * FROM tbl_reservation WHERE status = 'Delivered' OR status = 'Cancelled' OR status = '' AND DATE(date_ordered) = DATE(now())-1 ");
}


//THEN DISPLAY ALL IN VARIABLE USING WHILE LOOP AS mysql_fetch_array
//Display data here
//..
//..
//..
?>

订单日期 = 2016-10-09 [今天]
订单日期 = 2016-10-08 [昨天]
没有错误。
当我选择今天的过滤时..它会显示所有数据以及昨天的数据
但是当我选择昨天时..它会显示所有数据以及今天的数据

我希望的是纠正数据查询。有人可以帮忙吗？谢谢。

Answer 1

当您从日期中减去 1 时，它不会达到您想要的效果:MySql 然后将日期转换为数字并从中减去 1。这不会在本月的第一天给出预期的结果。

因此请使用 date_add 或 date_sub 而不是 -1，例如:

date_sub(date(now()), interval 1 day)

其次，逻辑运算符and优先于or，所以当你这样写时:

WHERE status = 'Delivered' 
   OR status = 'Cancelled' 
   OR status = '' 
  AND date(date_ordered) = date(now())

评估为:

WHERE status = 'Delivered' 
   OR status = 'Cancelled' 
   OR (status = '' AND date(date_ordered) = date(now()))

...这意味着当状态为“已交付”或“已取消”时，日期条件不起作用。

您可以通过在 OR 部分添加括号来解决此问题，或者您也可以从 IN 运算符中受益:

WHERE status IN ('Delivered', 'Cancelled', '')
  AND date(date_ordered) = date(now()))

.. 对于第二个 SQL 语句:

WHERE status IN ('Delivered', 'Cancelled', '')
  AND date(date_ordered) = date_sub(date(now()), interval 1 day)