Difference between link and join

[#1]

Hi friends,

I am getting confused between exact use of link and joins.

Can someone help me out in exact difference between link and joins.

Thanks in advance

[Ralf-Narfeldt]

This is a good technical brief by HIC in this topic:

Joins and Lookups

[avinashelite]

Hi Praful,

In Qlikview the join and link s are bit different, let me  try to put some words on it.

In Qlikview link means the two objects are linked by a common field i.e its kind of outer join without merging the tables and qlikview makes association based on this common filed.

e.g

table1

a

b

table2

a

c

if you have such script statements then the two tables are linked by field a and tables are not combined here

e.g

table1

a

b

join(table1)

table2

a

c

In the above eg we have used join, in this case it will combine both the tables and make it as one single table.

result

table1

a

b

c

[MK_QSL]

Two Tables are linked means they are linked with one or more than one common field(s). The final output is two different tables...

Example:

Sales:
Load CustomerID, Sales, Date From SalesTable;

Customer:

Load CustomerID, CustomerName From CustomerTable;

Here there are two tables linked(associated) in the data model by the common key CustomerID. So even though if you select Date, you will get respective CusotmerName due to the association.

Two Tables are joined means they are joined by one or more than one common fields(s).. The final output of the data model is only a single table.. in case if you have dropped the first table..

Example:

Sales:
Load CustomerID, Sales, Date From SalesTable;

Left Join(Sales)

Customer:

Load CustomerID, CustomerName From CustomerTable;

Here you will get the same result by selecting Date but the Data Model contains only Sales Table..

[mukesh24]

Hi,

Please check following links

Understanding Join, Keep and Concatenate

[jagan]

Hi,

Link and Joins are two different concepts, suppose if you have Customer and Orders table then both this tables are linked by using CustomerID.

Join means joins two tables into one by using Left, Right, Inner etc.  Check below link for Joins

Understanding Join, Keep and Concatenate

Regards,

Jagan.