循环遍历多维数组，检查PHP中的重复值的特定键

Question

I have a multi dimensional array that I have got from a database and I want to check this array for duplicate data and store it in another array of duplicates. my code is as follows

    //create temp array
    $tmp = array();

    foreach ($matchingarray as $nameKey => $match) {
          // loop through and stoe the contents of that array to another so i can compare
          $tmp[] = $match;
    }
     // create an array to store duplicates
    $duplicatesArray = array();
    // if the temp array is not empty then loop through both arrays 
    if (! empty($tmp)) {
        foreach ($tmp as $key => $tmpvalue) {
            foreach ($matchingarray as $key => $match) {
               // if a key name is the same in both arrays then add it tothe duplicates array
               if ($tmpvalue['name'] == $match['name']) {
                   $duplicatesArray = $match;
                   }
                }
            }
        }
       //count how many are duplicates
       $dups = count($duplicatesArray);

What I would like to know is this the right logic?

Answer 1

I will take where Igoel left off

there is 1 error and also 1 suggest that i will make.

Error: you cannot reuse $key twice in the foreach because they will override.

Suggestion as what Igoel stated: your best bet for duplicate effectively is to use sql. SQL is faster at processing than looping through arrays. Don't forget you need to load the data into memory and thats costly.