在关联数组中查找重复值,并将其添加到计数中 [英] Look for duplicate values in a associative array and add them to a count
问题描述
我正在尝试计算如下关联数组中重复值的数量:
Hi I am trying to count the number of duplicate values in a associative array that looks like this:
array(3) { [0]=> array(3) { ["Title"]=> string(25) "hello"
["Price"]=> int(50)
["Count"]=> int(1) }
[1]=> array(3) { ["Title"]=> string(35) "world"
["Price"]=> int(50)
["Count"]=> int(1) }
[2]=> array(3) { ["Title"]=> string(25) "hello"
["Price"]=> int(50)
["Count"]=> int(1) } }
如您所见,在标题"标签中有一个重复的值,我想对它们进行计数并将一个值添加到计数"部分.我开始做这样的事情:
As you can see here there is a duplicate value in the "Title" lable I want to count them and add one to the "Count" part. I started to do something like this:
$prodArray = array();
// Add the values to the array if it's the first time it occurs.
if (!in_array($row['prodTitle'], $prodArray["Title"]))
{
array_push($prodArray,
array( Title => $row['prodTitle'],
Price => $row['prodPrice'],
Count => 1)
);
}
else
{
//Add one to the count for the current item.
}
问题是我无法通过in_array函数访问数组中的"Title"元素.欢迎任何建议.
the thing is I can't access the "Title" element in the array through the in_array function. Any suggestions are welcome.
推荐答案
如果要检测正在创建的数组中的重复项,则可以避免多次遍历该数组:
If you want to detect dups in an array that you are creating, something like this avoid having to go through the array multiple times:
$arr=array();
while($row = mysql_fetch_array($result)) {
$arr[$row['prodTitle']] = isset($arr[$row['prodTitle']])
? $arr[$row['prodTitle']] +1
: 0;
}
$dups = array_keys(array_filter($arr)); //any key => 0 will be filtred out
如果您只想通过SQL直接获取dups,请查看以下内容:
If you want to just get the dups directly by SQL, have a look at this:
您当前的查询-
SELECT prodTitle
FROM product
WHERE prodTitle != '{$keyword}'
AND creditCard IN( SELECT creditCard FROM product WHERE prodTitle ='{$keyword}');
给出了这样的数据
prod cc
A 1
A 2
A 3
A 1
A 1
B 15
B 1
B 2
B 21
C 10
C 1
返回此集合(带有$ keyword =='A'):
returns this set (with $keyword=='A'):
prod
B
B
C
仅返回 记录的汇总查询,其中在非X上使用的信用卡也至少在X上使用过两次-
An aggregate query that returns only records where credit cards used on non-X were also used on X at least twice --
SELECT p1.prodTitle, COUNT(p2.creditCard) AS numrecords
FROM product p1
JOIN product p2
ON (p1.creditCard = p2.creditCard)
WHERE p1.prodTitle != '{$keyword}'
AND p2.prodTitle = '{$keyword}'
GROUP BY p1.prodTitle
HAVING COUNT(p2.creditCard) > 1;
给定相同的数据,返回此集合:
given the same data, returns this set:
prod num
B 2
执行聚合查询可以避免所有关于循环的混乱.这是链接到MySQL聚合列表功能.
Doing an aggregate query avoids all the messing about with loops. Here's a link to the MySQL list of aggregate functions.
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