I have the following array containing a master record of training courses held on a system (`select_group` just identifies related course groups):

```
Array
(
    [DE00041-1] => Array
        (
            [select_group] => 1
        )
)

```

The training course ids are then queried against a table containing only running courses whilst also grabbing extra information. 

As one training course may run more than once per year they have a `running_id` which gives the following:

```
Array
(
    [DE00041-1] => Array
        (
            [title] => xxx
            [405] => Array
                (
                    [start_quarter] => 1
                    [end_quarter] => 1
                )
        )
)

```

What I then need to do is add the original array `select_group` data into the newly created array.

The end result should be:

```
Array
(
    [DE00041-1] => Array
        (
            [title] => xxx
            [select_group] => 1
            [405] => Array
                (
                    [start_quarter] => 1
                    [end_quarter] => 1
                )
        )
)

```

I have looked over other SO / Google answers but couldn't find what I was looking for.

There may be 1-20 training courses listed, each one running once to four times per year.