topic Re: questions in QlikView

questions

prabhas277 — Fri, 17 Jul 2015 03:32:02 GMT

Hi,

Please find the below question and give the suitable answers...

1.What is FieldValue() ? What is the restriction on this function?

2.Explain me with scenarios of Primary Key and Perfect Key?

3.what is Used Bubble Sort? In which scenario we should use?

4. What is 3 Value Logic in Qlikview ?Can you Elaborate in Detail?

5.If I Want to Skip specific rows in Excel during Load how do we need to do that?

6.what is AGGR and Aggregation function? Both are same functions or not? if not same then what is major difference between them and give the example for that?

Re: questions

Fri, 17 Jul 2015 04:37:03 GMT

What is FieldValue() ? What is the restriction on this function?

TableB:

load * Inline

[

x,A,B,C, Name

10,5,2,1, Ram

20,4,5,2,David

30,6,8,7,James

];

=FieldValue('Name',1) will return Ram

=FieldValue('Name',2) will return David

=FieldValue('Name',3) will return James

Explain me with scenarios of Primary Key and Perfect Key?

[Perfect Key] indicates that every row contains a key value, and that all of these key values are unique. At the same time, the field's subset ratio is 100 percent. This qualifier should be seen in dimension tables, where every key should uniquely identify a single record.

[Primary Key] indicates that all key values are unique, but not every row contains a key value or the field's subset ratio is less than 100 percent

[Key] indicates that the key is not unique. This qualifier is usually seen in fact tables, where the same dimension value may be associated with many different facts."

Re: questions

Fri, 17 Jul 2015 04:37:55 GMT

what is Used Bubble Sort? In which scenario we should use?

Bubble Sort

In the bubble sort, as elements are sorted they gradually "bubble" (or rise) to their proper location in the array, like bubbles rising in a glass of soda. The bubble sort repeatedly compares adjacent elements of an array. The first and second elements are compared and swapped if out of order. Then the second and third elements are compared and swapped if out of order. This sorting process continues until the last two elements of the array are compared and swapped if out of order.

When this first pass through the array is complete, the bubble sort returns to elements one and two and starts the process all over again. So, when does it stop? The bubble sort knows that it is finished when it examines the entire array and no "swaps" are needed (thus the list is in proper order). The bubble sort keeps track of occurring swaps by the use of a flag.

The table below follows an array of numbers before, during, and after a bubble sort for descending order. A "pass" is defined as one full trip through the array comparing and if necessary, swapping, adjacent elements. Several passes have to be made through the array before it is finally sorted.

Array at beginning: 84 69 76 86 94 91

After Pass #1: 84 76 86 94 91 69

After Pass #2: 84 86 94 91 76 69

After Pass #3: 86 94 91 84 76 69

After Pass #4: 94 91 86 84 76 69

After Pass #5 (done): 94 91 86 84 76 69

The bubble sort is an easy algorithm to program, but it is slower than many other sorts. With a bubble sort, it is always necessary to make one final "pass" through the array to check to see that no swaps are made to ensure that the process is finished. In actuality, the process is finished before this last pass is made.

Re: questions

Fri, 17 Jul 2015 04:40:31 GMT

What is 3 Value Logic in Qlikview ?Can you Elaborate in Detail?

Three-value Logic (QlikView and SQL Database implement Three-Value Logic defined by Cole Kleene). This logic is implemented to handle NULLS in QlikView

Re: questions

maxgro — Fri, 17 Jul 2015 04:49:25 GMT

3.what is Used Bubble Sort? In which scenario we should use?

is an algorithm

Bubble sort - Wikipedia, the free encyclopedia

4. What is 3 Value Logic in Qlikview ?Can you Elaborate in Detail?

maybe this?

Null Value Handling using 3 Value Logic

5. If I Want to Skip specific rows in Excel during Load how do we need to do that?

add a where clause as in other load, example

load *

FROM

excelfile.xlsx (ooxml, embedded labels, table is Sheet1)

where prod like 'abc*';

where match(prod, 'abc', 'def');

where prod='abc'or prod='def';

6. what is AGGR and Aggregation function? Both are same functions or not? if not same then what is major difference between them and give the example for that?

Aggregations and Function Classes

Re: questions

Fri, 17 Jul 2015 04:53:09 GMT

If I Want to Skip specific rows in Excel during Load how do we need to do that?

https://community.qlik.com/thread/37828

LOAD @1,

@2,

@3,

@4,

@5,

@6,

@7,

@8,

FROM

[Test.xls]

(biff, no labels, table is sheet1$)

where RowNo()<1000;

You can replace the 1000 by the number of lines you want to load.

https://community.qlik.com/thread/53876