1.
Q1. Design a
mapping to load a target table with the following values from the above source?
department_no, employee_list
10, A
10, A,B
10, A,B,C
10, A,B,C,D
20, A,B,C,D,P
20, A,B,C,D,P,Q
20, A,B,C,D,P,Q,R
20, A,B,C,D,P,Q,R,S
Solution:
Step1: Use a sorter transformation and sort the data using the sort key as department_no and then pass the output to the expression transformation. In the expression transformation, the ports will be
department_no
employee_name
V_employee_list = IIF(ISNULL(V_employee_list),employee_name,V_employee_list||','||employee_name)
O_employee_list = V_employee_list
Step2: Now connect the expression transformation to a target table.
Q2. Design a mapping to load a target table with the following values from the above source?
department_no, employee_list
10, A
10, A,B
10, A,B,C
10, A,B,C,D
20, P
20, P,Q
20, P,Q,R
20, P,Q,R,S
Solution:
Step1: Use a sorter transformation and sort the data using the sort key as department_no and then pass the output to the expression transformation. In the expression transformation, the ports will be
department_no
employee_name
V_curr_deptno=department_no
V_employee_list = IIF(V_curr_deptno! = V_prev_deptno,employee_name,V_employee_list||','||employee_name)
V_prev_deptno=department_no
O_employee_list = V_employee_list
Step2: Now connect the expression transformation to a target table.
Q3. Design a mapping to load a target table with the following values from the above source?
department_no, employee_names
10, A,B,C,D
20, P,Q,R,S
Solution:
The first step is same as the above problem. Pass the output of expression to an aggregator transformation and specify the group by as department_no. Now connect the aggregator transformation to a target table.
department_no, employee_list
10, A
10, A,B
10, A,B,C
10, A,B,C,D
20, A,B,C,D,P
20, A,B,C,D,P,Q
20, A,B,C,D,P,Q,R
20, A,B,C,D,P,Q,R,S
Solution:
Step1: Use a sorter transformation and sort the data using the sort key as department_no and then pass the output to the expression transformation. In the expression transformation, the ports will be
department_no
employee_name
V_employee_list = IIF(ISNULL(V_employee_list),employee_name,V_employee_list||','||employee_name)
O_employee_list = V_employee_list
Step2: Now connect the expression transformation to a target table.
Q2. Design a mapping to load a target table with the following values from the above source?
department_no, employee_list
10, A
10, A,B
10, A,B,C
10, A,B,C,D
20, P
20, P,Q
20, P,Q,R
20, P,Q,R,S
Solution:
Step1: Use a sorter transformation and sort the data using the sort key as department_no and then pass the output to the expression transformation. In the expression transformation, the ports will be
department_no
employee_name
V_curr_deptno=department_no
V_employee_list = IIF(V_curr_deptno! = V_prev_deptno,employee_name,V_employee_list||','||employee_name)
V_prev_deptno=department_no
O_employee_list = V_employee_list
Step2: Now connect the expression transformation to a target table.
Q3. Design a mapping to load a target table with the following values from the above source?
department_no, employee_names
10, A,B,C,D
20, P,Q,R,S
Solution:
The first step is same as the above problem. Pass the output of expression to an aggregator transformation and specify the group by as department_no. Now connect the aggregator transformation to a target table.
Solution:
In the expression transformation, create a variable port and increment it by 1. Then assign the variable port to an output port. In the expression transformation, the ports are:
V_count=V_count+1
O_count=V_count
2. Design a mapping to load the first 3 rows from a flat file into a target?
Solution:
You have to assign row numbers to each record. Generate the row numbers either using the expression transformation as mentioned above or use sequence generator transformation.
Then pass the output to filter transformation and specify the filter condition as O_count <=3
3. Design a mapping to load the last 3 rows from a flat file into a target?
Solution:
Consider the source has the following data.
col
a
b
c
d
e
Step1: You have to assign row numbers to each record. Generate the row numbers using the expression transformation as mentioned above and call the row number generated port as O_count. Create a DUMMY output port in the same expression transformation and assign 1 to that port. So that, the DUMMY output port always return 1 for each row.
In the expression transformation, the ports are
V_count=V_count+1
O_count=V_count
O_dummy=1
The output of expression transformation will be
col, o_count, o_dummy
a, 1, 1
b, 2, 1
c, 3, 1
d, 4, 1
e, 5, 1
Step2: Pass the output of expression transformation to aggregator and do not specify any group by condition. Create an output port O_total_records in the aggregator and assign O_count port to it. The aggregator will return the last row by default. The output of aggregator contains the DUMMY port which has value 1 and O_total_records port which has the value of total number of records in the source.
In the aggregator transformation, the ports are
O_dummy
O_count
O_total_records=O_count
The output of aggregator transformation will be
O_total_records, O_dummy
5, 1
Step3: Pass the output of expression transformation, aggregator transformation to joiner transformation and join on the DUMMY port. In the joiner transformation check the property sorted input, then only you can connect both expression and aggregator to joiner transformation.
In the joiner transformation, the join condition will be
O_dummy (port from aggregator transformation) = O_dummy (port from expression transformation)
The output of joiner transformation will be
col, o_count, o_total_records
a, 1, 5
b, 2, 5
c, 3, 5
d, 4, 5
e, 5, 5
Step4: Now pass the ouput of joiner transformation to filter transformation and specify the filter condition as O_total_records (port from aggregator)-O_count(port from expression) <=2
In the filter transformation, the filter condition will be
O_total_records - O_count <=2
The output of filter transformation will be
col o_count, o_total_records
c, 3, 5
d, 4, 5
e, 5, 5
4. Design a mapping to load the first record from a flat file into one table A, the last record from a flat file into table B and the remaining records into table C?
Solution:
This is similar to the above problem; the first 3 steps are same. In the last step instead of using the filter transformation, you have to use router transformation. In the router transformation create two output groups.
In the first group, the condition should be O_count=1 and connect the corresponding output group to table A. In the second group, the condition should be O_count=O_total_records and connect the corresponding output group to table B. The output of default group should be connected to table C.
