Whenever I have some records/objects that I want to be in a certain order, I usually create a field called Ordinal.
I often wonder if it would be better to use an integer or a decimal value for the ordinal field.
This is a consideration when moving an object to a different position in the order:
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If you use consecutive integers, you have to do some serious reworking of all of the ordinals (or at least the ordinals that fall before the original position of the object being moved).
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If you use integers but space them out (maybe at 1000 intervals), then you can just change the ordinal to a mid point value between the surrounding objects where you want to move the object. This could fail if somewhere down the line you end up with consecutive integers.
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If you use decimal numbers you could just find the average of the surround object’s ordinals and use that for the object to be moved.
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Maybe it would be possible to use a string, but I could see that getting pretty goofy.
I’m sure there are other considerations I haven’t thought of.
What do you use and why?
“This could fail if somewhere down the line you end up with consecutive integers.”
For this (probably rare and thus not performance important) case, you could implement a renumber method that spaces out again. When I used to program in COMAL (anyone know that language?), you could do this very thing with line numbers.