Databases
StackOverflow2013
Postsdbo
POWhat's the best logic for grouping objects by closest start and end dates?
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POWhat's the best logic for grouping objects by closest start and end dates?
    primarykey
    data
    text
    <p>I have an array of items that all have start and end dates associated with them. I'd like to group them according to closest start and end dates without any of them overlapping, but I'm having difficulty conjuring what the logic for this should look like.</p> <p>Let's say I start with this:</p> <pre><code>$query = array( [0] =&gt; array( [0] =&gt; array( ['name'] =&gt;'A' ['start'] =&gt;'1/1/2011' ['end'] =&gt;'1/31/2011' ) [1] =&gt; array( ['name'] =&gt;'B' ['start'] =&gt;'1/15/2011' ['end'] =&gt;'1/31/2011' ) [2] =&gt; array( ['name'] =&gt;'C' ['start'] =&gt;'2/1/2011' ['end'] =&gt;'2/28/2011' ) [3] =&gt; array( ['name'] =&gt;'D' ['start'] =&gt;'2/2/2011' ['end'] =&gt;'2/28/2011' ) [4] =&gt; array( ['name'] =&gt;'E' ['start'] =&gt;'1/31/2011' ['end'] =&gt;'3/1/2011' ) [5] =&gt; array( ['name'] =&gt;'F' ['start'] =&gt;'3/3/2011' ['end'] =&gt;'3/31/2011' ) ) ) </code></pre> <p>And I want to finish with this:</p> <pre><code>$result = array( [0] =&gt; array( [0] =&gt; array( ['name'] =&gt;'A' ['start'] =&gt;'1/1/2011' ['end'] =&gt;'1/31/2011' ) [1] =&gt; array( ['name'] =&gt;'C' ['start'] =&gt;'2/1/2011' ['end'] =&gt;'2/28/2011' ) [2] =&gt; array( ['name'] =&gt;'F' ['start'] =&gt;'3/3/2011' ['end'] =&gt;'3/31/2011' ) ) [1]=&gt; array( [0] =&gt; array( ['name'] =&gt;'B' ['start'] =&gt;'1/15/2011' ['end'] =&gt;'1/31/2011' ) [1] =&gt; array( ['name'] =&gt;'D' ['start'] =&gt;'2/2/2011' ['end'] =&gt;'2/28/2011' ) ) [2]=&gt; array( [0] =&gt; array( ['name'] =&gt;'E' ['start'] =&gt;'1/31/2011' ['end'] =&gt;'3/1/2011' ) ) ) </code></pre> <p>edit: by request, the var_export for the input and output listed above:</p> <pre><code>$query = array ( 0 =&gt; array ( 'name' =&gt; 'A', 'start' =&gt; '1/1/2011', 'end' =&gt; '1/31/2011', ), 1 =&gt; array ( 'name' =&gt; 'B', 'start' =&gt; '1/15/2011', 'end' =&gt; '1/31/2011', ), 2 =&gt; array ( 'name' =&gt; 'C', 'start' =&gt; '2/1/2011', 'end' =&gt; '2/28/2011', ), 3 =&gt; array ( 'name' =&gt; 'D', 'start' =&gt; '2/2/2011', 'end' =&gt; '2/28/2011', ), 4 =&gt; array ( 'name' =&gt; 'E', 'start' =&gt; '1/31/2011', 'end' =&gt; '3/1/2011', ), 5 =&gt; array ( 'name' =&gt; 'F', 'start' =&gt; '3/3/2011', 'end' =&gt; '3/31/2011', ), ) $result = array ( 0 =&gt; array ( 0 =&gt; array ( 'name' =&gt; 'A', 'start' =&gt; '1/1/2011', 'end' =&gt; '1/31/2011', ), 1 =&gt; array ( 'name' =&gt; 'C', 'start' =&gt; '2/1/2011', 'end' =&gt; '2/28/2011', ), 2 =&gt; array ( 'name' =&gt; 'F', 'start' =&gt; '3/3/2011', 'end' =&gt; '3/31/2011', ), ), 1 =&gt; array ( 0 =&gt; array ( 'name' =&gt; 'B', 'start' =&gt; '1/15/2011', 'end' =&gt; '1/31/2011', ), 1 =&gt; array ( 'name' =&gt; 'D', 'start' =&gt; '2/2/2011', 'end' =&gt; '2/28/2011', ), ), 2 =&gt; array ( 0 =&gt; array ( 'name' =&gt; 'E', 'start' =&gt; '1/31/2011', 'end' =&gt; '3/1/2011', ), ), ) </code></pre> <p>The best I have so far is to loop through the items in $query, and for each one, compare the start date to the end date of the last item in each of the arrays. Even as I'm typing this out I'm realizing that that would assume we're starting with a $query array that's already in some sort of chronological order (it's random.) </p> <p>We are trying to put a GANTT timeline together with this data, using as few rows as possible to help visualize what our open schedule looks like. It has me stumped. Anyone who can point to the most efficient method of organizing these objects, it'd be greatly appreciated.</p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USTJ Nicolaides
    1. USTJ Nicolaides
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. COThe term "Closest start and end dates" is not really precise... You show great input and output but we still need to understand that point if you want us to provide any suggestions...
      singulars
      1. POWhat's the best logic for grouping objects by closest start and end dates?
      1. USMathieu Dumoulin
    2. COconsider adding var_export() output to make it easy for people to try to help.
      singulars
      1. POWhat's the best logic for grouping objects by closest start and end dates?
      1. USgoat
    3. CO@MathieuDumoulin - another way of phrasing the task - I want to arrange objects into as few groups as possible, with as few gaps between starts and ends as possible. If Object C's start date is 3 days removed from Object A, but only 1 day removed from Object B, I want it to go into the group with Object B.
      singulars
      1. POWhat's the best logic for grouping objects by closest start and end dates?
      1. USTJ Nicolaides
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload