dcsimg
Login | Register   
LinkedIn
Google+
Twitter
RSS Feed
Download our iPhone app
TODAY'S HEADLINES  |   ARTICLE ARCHIVE  |   FORUMS  |   TIP BANK
Browse DevX
Sign up for e-mail newsletters from DevX

By submitting your information, you agree that devx.com may send you DevX offers via email, phone and text message, as well as email offers about other products and services that DevX believes may be of interest to you. DevX will process your information in accordance with the Quinstreet Privacy Policy.


Tip of the Day
Language: Relational Databases
Expertise: Beginner
Dec 23, 1997

WEBINAR:

On-Demand

Building the Right Environment to Support AI, Machine Learning and Deep Learning


Calculating the Records

Question:
Can you help me to get a calculated value from many records? A dataset(Paradox table) that I use has an Integer field which is used to put minutes value. How do I add up the value of these fields on many records? In other words, I want to calculate same fields for multiple records in one dataset. I am using DBGrid, and this dataset is a detail table for a master. Thank you. Stan

Answer:
There are two ways to do this: 1) You can drop a TQuery on your form and set it up to run at runtime to sum that field like so:

SELECT Sum(IntField) as IntFieldSum
FROM "MyTable.DB"
Then in the OnCalcFields method for the DBGrid, you can just set the value to
Query1.FieldByName('IntFieldSum).AsInteger;
2) The other way is to scan through the table and do an incremental add. Notice that I didn't put the query in the OnCalcFields method. This is because it would execute everytime you entered a record or made a change - not good. The second method is NOT recommended, especially if you have a lot of records in the table.
DevX Pro
 
Comment and Contribute

 

 

 

 

 


(Maximum characters: 1200). You have 1200 characters left.

 

 

Sitemap
Thanks for your registration, follow us on our social networks to keep up-to-date