difference between times returns a value
in [General]
|
From: Wayne-I-M on 5 May 2010 07:18 Hi When you speak of columns/fields it sounds to me as is you are working on the table itself. The table is just there hold data and a few other (very few) things. You really should not be working on it. If you to you can create a quesry based on the table and it will look a little like the table. You can then add a caculated column using the formual that Stefan and Ronaldo gave you. Don't store the results of a calculation - for lots of reasons. You can get the results whenever you want. You can us the result with other calculations, you can print it in a report, etc, etc. But the main thing is that if the base of the calculation ever changes then the result will still be correct. OK there are a (very) few time when you should save the results - I do this for a currency conversion calculation as I don't save the base (the amounts and rates) as I am only interested in the result. But for almost all calculation you really should not store the result. Hope this helps -- Wayne Manchester, England. "Charno" wrote: > I know its a bit of an Access sin, but could the value be returned to the > table? > > "RonaldoOneNil" wrote: > > > Set the control source property of your adhearance field to > > =IIf(DateDiff("n",[DRSR Time],[Gate Time])<=60,"Hit","Miss") > > > > "Charno" wrote: > > > > > I have a table/form which i have 2 columns/fields which time is entered. > > > "DRSR Time" and "Gate Time". > > > What i'm trying to do is return the value 'Hit' (if the difference between > > > the 2 times is less than 60 mins) or 'Miss' (if it is greater than 60 mins), > > > in a 3rd column/field called "adhearance". > > > > > > Any help would be great, > > > > > > Thanks > > > > > > > > >
From: Charno on 5 May 2010 08:08 Thanks Wayne, I kind of thought that i shouldn't be working on the table, but i thought i would ask the question just incase i was missing something. Using the formula's i was given i created a query and then added it as a subform on my form. Thanks to everyone for the help, much appreciated :) Charno "Wayne-I-M" wrote: > Hi > > When you speak of columns/fields it sounds to me as is you are working on > the table itself. The table is just there hold data and a few other (very > few) things. > You really should not be working on it. > > If you to you can create a quesry based on the table and it will look a > little like the table. > You can then add a caculated column using the formual that Stefan and > Ronaldo gave you. > Don't store the results of a calculation - for lots of reasons. You can get > the results whenever you want. You can us the result with other > calculations, you can print it in a report, etc, etc. But the main thing is > that if the base of the calculation ever changes then the result will still > be correct. > OK there are a (very) few time when you should save the results - I do this > for a currency conversion calculation as I don't save the base (the amounts > and rates) as I am only interested in the result. But for almost all > calculation you really should not store the result. > > Hope this helps > > > -- > Wayne > Manchester, England. > > > > "Charno" wrote: > > > I know its a bit of an Access sin, but could the value be returned to the > > table? > > > > "RonaldoOneNil" wrote: > > > > > Set the control source property of your adhearance field to > > > =IIf(DateDiff("n",[DRSR Time],[Gate Time])<=60,"Hit","Miss") > > > > > > "Charno" wrote: > > > > > > > I have a table/form which i have 2 columns/fields which time is entered. > > > > "DRSR Time" and "Gate Time". > > > > What i'm trying to do is return the value 'Hit' (if the difference between > > > > the 2 times is less than 60 mins) or 'Miss' (if it is greater than 60 mins), > > > > in a 3rd column/field called "adhearance". > > > > > > > > Any help would be great, > > > > > > > > Thanks > > > > > > > > > > > >
From: John W. Vinson on 5 May 2010 12:38
On Wed, 5 May 2010 03:24:01 -0700, Charno <Charno(a)discussions.microsoft.com> wrote: >I know its a bit of an Access sin, but could the value be returned to the >table? Storing derived data such as this in your table accomplishes three things: it wastes disk space; it wastes time (almost any calculation will be MUCH faster than a disk fetch); and most importantly, it risks data corruption. If one of the underlying fields is subsequently edited, you will have data in your table WHICH IS WRONG, and no automatic way to detect that fact. Just redo the calculation whenever you need it, either as a calculated field in a Query or in the control source of a Form or a Report textbox. -- John W. Vinson [MVP] |