what it does?

[soniasweety]

Hi all,

what is this use and how it will work can anyone explain?

    AutoNumber(Trim(identifier&code&line&date   &product&manufac&product_id&channel)) as "_KEY";

[qlikviewwizard · Accepted solution]

Hi soniasweety

Trim() removes the spaces before and after the value of the filed.

Trim( ' abc' ) Returns 'abc'

Trim( 'abc ' ) Returns 'abc'

Trim( ' abc ' ) Returns 'abc'

Autonumber will give numeric values from 1 to number of values of the field.

We can generate serial numbers by concatenating/joing more than one field. For example as your KEY filed.

Example :

Autonumber(Field1&Field2&Field3) as Key

RegionSales: LOAD *, AutoNumber(Region&Year&Month) as RYMkey; LOAD * INLINE [ Region, Year, Month, Sales North, 2014, May, 245 North, 2014, May, 347 North, 2014, June, 127 South, 2014, June, 645 South, 2013, May, 367 South, 2013, May, 221 ];

The resulting table looks like this:

Region	Year	Month	Sales	RYMkey
North	2014	May	245	1
North	2014	May	347	1
North	2014	June	127	2
South	2014	June	645	3
South	2013	May	367	4
South	2013	May	221

[sibin_jacob]

In simple words

It is creating a unique key by combining multiple columns.

It may be because, there no column value is unique.

then using this key to join with other tables.

It is better to have join key as numeric to improve the performance, so it is using Autonumber function to create the numeric value for combined column values.

Trim function to trim the values (remove the space).