Mapping Load in Qlikview is very good and useful concept in data modelling it is provide strong and very useful for joining tables. In mapping the statement MAPPING provides an table to join with its look up table. By using this keyword the mapping table is joins with the table with use of the APPLYMAP key words.
Prefix MAPPING is used to the load the table as mapping table and before load keyword we used Mapping statement to tell Qlikview load script that a table is a mapping table.
Mapping Load Script:-
And after this when we load the Mapping table we load the table and use APPLYMAP in the table to map the mapping table data.
By the help of the ApplyMap() function we can map the mapping table by use APPLYMAP
Syntax for Applymap:-
ApplyMap (‘Mapping Table Name’, MapField Name, ‘Default Expression’)
How to use the Applymap() function in any load script now i explain here how to use the Applymap function in the load script.
Basic Requirement for the Mapping load:-
- Mapping load table has minimum and compulsory have two columns. The first column has being the lookup value for the table and the second column has being the mapping value to return the column to the table where Applymap is used.
- When Mapping key word is used in the table the table is loaded but is it temporary table. When the mapping is done in the reload engine then the table is automatically remove from the QlikView reload engine and we can not able to see the table in data model for more you can see it by press Ctrl + T or from the Table Viewer option from design menu.
The final view of the table after mapping is perform you can see only single table.
Advantages of the Mapping Load:-
- Mapping load is fast.
- We have to use it in many table in the data date model.
- It can remove the duplicates in the table.
You can read more about the Data Modelling in Qlikview Here