Make one big table from several. Should use join?

[Madina]

Hello,

i have several(>15)  tables. Each has many columns, and they all have one column called  dates in common. So, each has the same dates, and each has only one row for each date.  What I want is to make one big table.  Is it ok to use join? I mean, i am not sure whether it is best practice. 
 
how i wrote like 

table a:

load  dates, a, b, … from A;

join (a)

table b:

load dates, d, f, … from B;

Join (a) 

table c:

load dates, q,w,… from C;

and etc. 

but not sure if it is good to do so. 

[AshutoshBhumkar]

Hi,

If Date is the only column which is common across all the tables and which is unique for rows then you can use it as a join key.

I would suggest to check the Date format while joining. (However Applymap() is the safe option)

Thanks,

Ashutosh

[Madina]

Hello, @AshutoshBhumkar  , thank you for your reple. Yes , date is only common column and I made them one view, like 'MM.DD.YYYY'

About applymap, can you give example how to use? I mean, not sure how to use it.  I should firstly load everything to different tables (like below)  and then generate one big table?

Lets say I firstly did like this  

table a:

load  dates,

a,

b,

…   from A;

table b:

load dates,

d,

f,

… from B;

table c:

load dates,

q,

w,

… from C;

                                    and etc. 

What should write next? 
Will be happy if you can answer

[AshutoshBhumkar · Accepted solution]

Sure.

Here is the link with definition and an example.

https://help.qlik.com/en-US/sense/August2023/Subsystems/Hub/Content/Sense_Hub/Scripting/MappingFunct...

When you say Date is unique for all the rows, you can use the Date as join key.

E.g 

table a:

load  dates,

a,

b,

…   from A;

 Left Join (table a)

table b:

load dates,

d,

f,

… from B;

  Left Join (table a)

table c:

load dates,

q,

w,

… from C;

This will create final table table a  with all the columns in one big table.