Expression is a passive transformation which is used to perform row level calculations.Expression transformation can also be used to test conditional statements before passing the data to other transformations.
Creating Expression Tranformation
Transformation: We can enter the transformation name and description, and can also make transformation make reusable.
Ports: Create and delete ports and configuring the new ports.
Properties: Configuring the tracing level to set the what type of session log we get.
Meta Data Extensions: We can specify extension name, data type, precision, value and can also create reusable meta data extension.
Configuring Ports:
Data Type: Select the data type.
Port Name: Adding and deleting ports.
Precision and Scale: Set the precision and scale for every port.
Variable Port: It holds the memory value.
Expression: Enter the logic or expression in expression editor.
Implementing Expression Transformation with Example
Creating Expression Tranformation
- In the mapping dessigner->Mpping->Create new mapping
- Go to Transformation->Select Expression Transformation->Specify Name->Create->done.
- We can add ports in expression dragging from previous transformation or we can create ports manually by opening ports tab.
- Adding Expressions in expression editor.
Transformation: We can enter the transformation name and description, and can also make transformation make reusable.
Ports: Create and delete ports and configuring the new ports.
Properties: Configuring the tracing level to set the what type of session log we get.
Meta Data Extensions: We can specify extension name, data type, precision, value and can also create reusable meta data extension.
Configuring Ports:
Data Type: Select the data type.
Port Name: Adding and deleting ports.
Precision and Scale: Set the precision and scale for every port.
Variable Port: It holds the memory value.
Expression: Enter the logic or expression in expression editor.
Implementing Expression Transformation with Example
- Drag source and target from repository to designer
- Go to transformation->create->Expression->OK
- Copy all the ports from source qualifier to filter.
- Edit Expression Transformation->ports->Add New port->O_ENAME-> Deselect the input port
- Click on expression Editor->From all functions-> select initcap->Initcap(ENAME)->Validate->OK
Connect remaining all ports from expression to trget.
Init cap Function shows the First alphabet in the ENAME column is capital
