1

Lets say this is my sql database column values:

Result  -      Reference

  1                A1
  2                A2
  3                A3
  4                A4
  5                A5

After fetching the above columns, I have the following arrays:

$inputValue = array(1,3,5);  //This is the User Input

$result = array(1,2,3,4,5); //This is the mysql fetched result of 'Results' column

$reference = array('A1','A2','A3','A4','A5'); //This is the fetched result of 'Reference' column

$filteredData = array_intersect($inputValue, $result);

print_r($filteredData);

When I do array_intersect($inputValue, $result); this gives the output: 

Array ( [0] => 1 
    [1] => 3 
    [2] => 5 )

Now after the array_intersect, how will I store the corresponding references into another array? Meaning, after the intersect, the $filteredData has the array values 1,3,5. Now I also want the corresponding references to be stored in a separate array which should have this value: $MatchingReference = array(A1,A3,A5);

How is this done?

Neel
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3 Answers3

2

I would try this:

$filteredReferences = array();
foreach($filteredData as $key) {
    $filteredReferences[] = $reference[$key-1];
}
Xardas
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  • I like your suggestion. But when I tried that, I am getting: `Notice: Undefined offset: 5 in C:\Users\test.php on line 18 Array ( [0] => A2 [1] => A4 [2] => )`. My line 18 is `$filteredReferences[] = $reference[$key];` – Neel Jan 17 '14 at 22:06
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    Remember that array indexes start at zero, not 1. – Bill Karwin Jan 17 '14 at 22:06
  • Just 1 typo. You need to add the semi-colon (;) at the end of 1st line. Tried editing it but it says edit needs to be atleast 6 characters. Cheers. – Neel Jan 17 '14 at 22:12
  • Hi Xardas, I did a few testing, but I think @BillKarwin approach is probably better. Your code works well with the example I had given where the array values are in order like 1,2,3,etc.. But if I have `$inputValue` as say '1,58,51' and `$result` array value as '1,2,58,4,51', then I will get an error since it is looking for `$reference[$key-1]`. – Neel Jan 17 '14 at 22:23
1

Combine the two arrays from the database into an associative array. Then use the user input to select only a subset of keys.

$filteredData = array_intersect_key(
    array_combine($result, $reference), 
    array_flip($inputValue)
);
Bill Karwin
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  • Your method works too. Both yours and Xardas suggestion does exactly what I wanted!. Fantastic :) – Neel Jan 17 '14 at 22:09
  • After a few testing, I think your method is the best approach. I had added my reason in the comment under @Xardas suggested answer. :) Thank you Bill. – Neel Jan 17 '14 at 22:25
1

If this was a task in my own application, I would definitely implement the data filter with SQL instead of PHP.

Otherwise, you going to need perform a few manipulations to enjoy efficient key-based filtration and reach your desired output. (Demo)

var_export(
    array_intersect_key(
        array_column($resultSet, 'reference', 'result'),
        array_flip($inputValue)
    )
);
mickmackusa
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  • Thank you @mickmackusa I am about to update the codes in my app this year as an upgrade process and I will review the above code and try your recommendation. thank you for sharing your suggestion. – Neel Feb 23 '22 at 03:20