Genrate the fibonacci series in informatica.

The source data contains only column 'id'. It will have sequence numbers from 1 to 1000. The source data looks like as
Id
1
2
3
4
5
6
7
8
....
1000

Create a workflow to load only the Fibonacci numbers in the target table. The target table data should look like as
Id
1
2
3
5
8
13
.....

In Fibonacci series each subsequent number is the sum of previous two numbers. Here assume that the first two numbers of the fibonacci series are 1 and 2. 

Solution:

STEP1:

Drag the source to the mapping designer and then in the Source Qualifier Transformation properties, set the number of sorted ports to one. This will sort the source data in ascending order. So that we will get the numbers in sequence as 1, 2, 3, ....1000

STEP2: Connect the Source Qualifier Transformation to the Expression Transformation. In the Expression Transformation, create three variable ports and one output port. Assign the expressions to the ports as shown below.

Ports in Expression Transformation:

id

v_sum = v_prev_val1 + v_prev_val2
v_prev_val1 = IIF(id=1 or id=2,1, IIF(v_sum = id, v_prev_val2, v_prev_val1) )
v_prev_val2 = IIF(id=1 or id =2, 2, IIF(v_sum=id, v_sum, v_prev_val2) )
o_flag = IIF(id=1 or id=2,1, IIF( v_sum=id,1,0) )

STEP3: Now connect the Expression Transformation to the Filter Transformation and specify the Filter Condition as o_flag=1

STEP4: Connect the Filter Transformation to the Target Table.