Add load and Concatenate

[vanderson009]

Hello Community,

What is difference between ADD Load and Concatenate.

-- Thanks and Regards,

Villyee Anderson.

[amit_saini]

Villyee,

Concatenate

Now let's look at Concatenate. Concatenate appends the rows of one table to another. Concatenate never merges any rows. The number of rows in a concatenated table is always the sum of the rows from the two input tables. Here's what our sample data will look like after Concatenate.

CONCATENATE (Table1) LOAD * RESIDENT Table2;

Key	A	C
1	A1
1		C1
2	A2
2		C2
3	A3
4		C4

Rows with like Key values are not merged together. The rows from Table2 are simply appended to Table1. Because the tables have different fields, rows will have null values for the fields from the "other" table.

s identical, they will be automatically concatenated and you end up with one table.

ADD

Simply put, this statement blindly appends data from one table to the data of another table, having similar signature, during partial reload. It does not check for any duplicate. Hence, ADD LOAD or ADD SELECT is usually follwed by distinct or a proper where clause.

e.g.

LOAD OrderID, OrderAmt from Order_May.csv;

ADD LOAD OrderID, OrderAmt from Order_June.csv;

This will simply concate data from Order_June to Order_May. But OrderID might be duplicated. Hence, this statement can be properly shaped to remove duplicate data as:

LOAD OrderID, OrderAmt from Order_May.csv;

ADD LOAD OrderID, OrderAmt from Order_June.csv Where Not Exists(OrderID);

For more details on load follow link below:

Types of loads in Qlikview

Thanks,

AS

[tresesco]

ADD is only relevant with partial reload.

Tab1:

LOAD Name, Number FROM Persons.csv;

ADD LOAD Name, Number FROM newPersons.csv;

During normal reload, data is loaded from Persons.csv and stored in the QlikView table Tab1. Data from NewPersons.csv is then concatenated to the same QlikView table.

During partial reload, data is loaded from NewPersons.csv and appended to the QlikView table Tab1. No check for duplicates is made.

Hence, these are different when the reload is partial.

[ashfaq_haseeb]

Hi

ADD Load Will be used for partial Reload.

Whereas Concatenate will be used to combine two tables.

Regards

ASHFAQ