Solved

Update query to determine if date is a weekend

Posted on 2014-11-06
13
166 Views
Last Modified: 2014-11-07
I want to update a field's value to the previous day's field value (if on a Saturday) or to the value of the day after (if on a Sunday). I'm not sure of the correct syntax.

I tried this:
UPDATE [Copy Of IMPORT_Current] SET [Copy Of IMPORT_Current].WATER = DateAdd("d",-1, [Copy Of IMPORT_Current]![DATE])
IIf (Weekday([Copy Of IMPORT_Current]![DATE],1) =7
 
but it's not the correct syntax and it doesn't utilize the "OR" criteria I'm aiming for.

Any help would be great!
Thanks,
KT
0
Comment
Question by:ktjamms2
  • 6
  • 6
13 Comments
 
LVL 24

Expert Comment

by:Phillip Burton
Comment Utility
Try this:

UPDATE [Copy Of IMPORT_Current] SET [Copy Of IMPORT_Current].WATER = DateAdd("d",
iif(Weekday([Copy Of IMPORT_Current]![DATE],1) =7,-1,iif(Weekday([Copy Of IMPORT_Current]![DATE],1) =1,1,0)), 
[Copy Of IMPORT_Current]![DATE])

Open in new window

0
 

Author Comment

by:ktjamms2
Comment Utility
Actually I need:

SET [Copy Of IMPORT_Current].WATER = [Copy Of IMPORT_Current].WATER of the day before
0
 
LVL 24

Expert Comment

by:Phillip Burton
Comment Utility
Which is why there is a -1 in line 2.
0
 

Author Comment

by:ktjamms2
Comment Utility
I'm not sure what you have, but it looks like its setting the value to a date.  I need the value set to the number value of the corresponding date:

SET [Copy Of IMPORT_Current].WATER = [Copy Of IMPORT_Current].WATER of the day before if the [Copy Of IMPORT_Current]![DATE] is a Saturday

or

SET [Copy Of IMPORT_Current].WATER = [Copy Of IMPORT_Current].WATER of the day after if the [Copy Of IMPORT_Current]![DATE] is a Sunday
0
 
LVL 24

Expert Comment

by:Phillip Burton
Comment Utility
What do you mean, "number value"?
0
 

Author Comment

by:ktjamms2
Comment Utility
rephrased:
Set Saturday's water values to Friday's water values
and Set Sunday's water values to Monday's water values
0
How to run any project with ease

Manage projects of all sizes how you want. Great for personal to-do lists, project milestones, team priorities and launch plans.
- Combine task lists, docs, spreadsheets, and chat in one
- View and edit from mobile/offline
- Cut down on emails

 

Author Comment

by:ktjamms2
Comment Utility
Explanation:
I don't get numbers for weekends. So, I want to just use the numbers for the day before or from the day after depending  on whether it's Saturday or Sunday
0
 
LVL 24

Expert Comment

by:Phillip Burton
Comment Utility
Now that you have the relevant date, in a second query, you do a Left Join with the original table to get the relevant date's value,
0
 
LVL 30

Expert Comment

by:hnasr
Comment Utility
List 3 records, and show required output.
0
 

Author Comment

by:ktjamms2
Comment Utility
ID            DATE                  WATER

20            11/1/2014            0
20            11/2/2014            225
20            11/3/2014            100      
20            11/4/2014            200
20            11/5/2014            350
20            11/6/2014            500
20            11/7/2014            220
20            11/8/2014            0

11/1/2014 IS A SUNDAY. THE WATER NEEDS TO BE UPDATED TO THE NEXT DAY'S WATER VALUE (11/2/2014, MONDAY). THAT VALUE WOULD BE 225

11/8/2014 IS A SATURDAY. THE WATER NEEDS TO BE UPDATED TO THE PREVIOUS DAY'S WATER VALUE (11/7/2014, FRIDAY). THAT VALUE WOULD BE 220

THERE ARE MULTIPLE IDs AND DATES IN THE TABLE. I ONLY SHOWED AN EXAMPLE OF ONE CASE FOR A WEEK IN THIS EXAMPLE.
0
 
LVL 24

Expert Comment

by:Phillip Burton
Comment Utility
Now that you have the relevant date, in a second query, you do a Left Join with the original table to get the relevant date's value,
0
 

Author Comment

by:ktjamms2
Comment Utility
I don't understand what you are saying----- "Now that you have the relevant date, in a second query, you do a Left Join with the original table to get the relevant date's value, "

Could you show the SQL code?
0
 
LVL 24

Accepted Solution

by:
Phillip Burton earned 500 total points
Comment Utility
Your original table is [Copy Of IMPORT_Current]

You create a new query, Query1, with the following code:
Select *, DateAdd("d",iif(Weekday([DATE],1) =7,-1,iif(Weekday([DATE],1) =1,1,0)), [DATE]) as NewDate
From [Copy Of IMPORT_Current]

Open in new window


Then you have another query which does the join:
Select Query1.*, [Copy Of IMPORT_Current].WATER
From Query1
Left join [Copy Of IMPORT_Current]
ON Query1.NewDate = [Copy Of IMPORT_Current].[DATE]

Open in new window

0

Featured Post

How to run any project with ease

Manage projects of all sizes how you want. Great for personal to-do lists, project milestones, team priorities and launch plans.
- Combine task lists, docs, spreadsheets, and chat in one
- View and edit from mobile/offline
- Cut down on emails

Join & Write a Comment

Suggested Solutions

Experts-Exchange is a great place to come for help with solutions for your database issues, and many problems are resolved within minutes of being posted.  Others take a little more time and effort and often providing a sample database is very helpf…
Overview: This article:       (a) explains one principle method to cross-reference invoice items in Quickbooks®       (b) explores the reasons one might need to cross-reference invoice items       (c) provides a sample process for creating a M…
Using Microsoft Access, learn some simple rules for how to construct tables in a relational database. Split up all multi-value fields into single values: Split up fields that belong to other things into separate tables: Make sure that all record…
What’s inside an Access Desktop Database. Will look at the basic interface, Navigation Pane (Database Container), Tables, Queries, Forms, Report, Macro’s, and VBA code.

763 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

6 Experts available now in Live!

Get 1:1 Help Now