AnsweredAssumed Answered

Data Field Level Validation; lengths, codes etc.

Question asked by johnenyedy on Oct 26, 2012
Latest reply on Nov 1, 2012 by LaRetta

I am rather new to FM, coming from FoxPro and there are several data level things that I am trying to understand. I am working on an HR system aimed at PC and Mac with a few hundred fields.

There are a number of these fields that are used for codes that currently are limited to a few characters and quite a few that are T or F.


I am concerned about performance and unforseen consequences.

  1. When should I limit the length of a text field? [ I know how to do this via Database field Options Validation --> Left( Trim( <fieldname> ); number ) ]
  2. When should I limit the length of a numeric field?
  3. Is there any reason NOT to limit a code field to a just few characters when it's value comes from a Drop-down List? [ again using Validation, forcing a List Value ]
  4. For T-F fields I am currently using a Yes-No List as the apparently easiest solution. Is there a better way? I know I could store it as a number 1 or 0 but then I need to deal with all the displays of Yes-No and I am not sure how to best do that.
  5. Are there any other field level things I should be concerened with.


I have read a book, watched hours of videos and searched forums. I have learned "How To" do the above but not the "Why" or "Why Not". It seems like the "Whys" have illuded me.


Thanks in advance for your thoughts.