whatis the main diffrence between query calculation and data item?

[bvk.cognoise]

Hi,

i have small confusion...what is the main difference between query calculation and datitem?


thanks
bvk

[blom0344]

A query calculation is semi-unique for a report, whereas a dataitem is usually reused from a model

[bvk.cognoise]

Hi blom0344,

thank you very much for your reply.but im not able to understand it.can you please explain me it clearly?


thanks
bvk

[blom0344]

Suppose your report fetches 2 facts (with other related dataitems) When you drag a new dataitem to the query and perform a subtraction with the 2 facts, then you are effectively creating a new query calculation. This exists in the report query, but not as a model query item

[bvk.cognoise]

Hi blom0344,

sorry for my mistake i did not asked my question clearly  :( .what i am asking is what  is the difference between Data item ,query calculation which is located in toolbox tab. we can create new calculated column using these two(Data item,query calculation).but in which case we use Data item and query calculation?

sorry for my uncleared question  :(

thanks
bvk