Creating a weekly array with multiple entries for each day

Question

I have a MySQL query that returns a dump of data like so (duplicates expected and needed for other columns that are excluded for this question):

SessionID  DayofWeek    SessionDetails  Description
1          Sunday       1:00 PM         Foo
1          Sunday       1:00 PM         Foo
1          Sunday       1:00 PM         Foo
1          Sunday       1:00 PM         Foo
2          Monday       10:00 AM        Foo
2          Monday       10:00 AM        Foo
2          Monday       10:00 AM        Foo
2          Monday       10:00 AM        Foo
3          Monday       7:00 PM         Barr
3          Monday       7:00 PM         Barr
3          Monday       7:00 PM         Barr
3          Monday       7:00 PM         Barr

I am trying to create an array for each day and only store the different session/times once in it, e.g.,

Sunday => Array (
       [SessionID] => 1
       [SessionDetails] => 1:00 PM
       [Description] => Foo
)
Monday=> Array (
       [SessionID] => 2
       [SessionDetails] => 10:00 AM
       [Description] => Foo
       [SessionID] => 3
       [SessionDetails] => 7:00 PM
       [Description] => Bar
)

I am setting a blank array for each day before my foreach ($sqlresults as $row) loop, like $sunday=array(); $monday=array(); etc.

Then inside the loop I am doing:

      if (!in_array($row['SessionID'],$sunday)){
          $sunday[]=array($row['SessionID'],$row['Description'], $row['SessionDetails']);
}

It sort-of-works but it's not checking the if (!in_array) part right and it's adding every single (duplicate) SessionID as a new array e.g.,

print_r($sunday)

Array
(
    [0] => Array
        (
            [0] => 1
            [1] => Foo
            [2] => 1 PM
        )
    [1] => Array
        (
            [0] => 1
            [1] => Foo
            [2] => 1 PM
        )
    [2] => Array
        (
            [0] => 1
            [1] => Foo
            [2] => 1 PM
        )
    [3] => Array
        (
            [0] => 1
            [1] => Barr
            [2] => 1 PM
    )
    [4] => Array
        (
            [0] => 2
            [1] => Barr
            [2] => 10 AM
        )

etc...

I tried to check the sessionID inside the array before adding to it:

if (!in_array($row['SessionID'][],$sunday)){

But "Fatal error: Cannot use [] for reading"

So I tried:

  if (!in_array($sunday[$row['SessionID']],$sunday)){

But "Notice: Undefined offset: 1"

I tried setting it to associative values:

      if (!in_array($row['SessionID'],$sunday)){
  $sunday[]=array("SessionID"=>($row['SessionID']),"Description"=>($row['Description']), "Time"=>($row['SessionDetails']));
}

Same problem, except the array is easier to read:

[0] => Array
    (
        [SessionID] => 1
        [Description] => Foo
        [Time] => 1 PM
    )
[1] => Array
    (
        [SessionID] => 1
        [Description] => Foo
        [Time] => 1 PM
    )

TLDR: How can I get it to check the index [SessionID] before trying to add to the day array?

Answer 1

Here's a simple way to do it using array_unique.

$result = [];

foreach (array_unique($rows, SORT_REGULAR) as $row) {
    $result[$row['DayofWeek']][] = $row;
}

You can run the code here.