Database Reference
In-Depth Information
Unconnected Lookup transformations
As mentioned, unconnected transformations are not connected to any other transformation,
source, or target by any links. An unconnected Lookup transformation is called by another
transformation with the
:LKP
function. Using the
:LKP
function, you can pass the re-
quired value to the input port of the Lookup transformation, and the return port passes the
output value back to the transformation from which the lookup was called. A mapping us-
ing an unconnected Lookup transformation is as follows:
In the preceding mapping, we are implementing the same scenario that we implement using
a connected Lookup transformation. Perform the following steps to implement this scen-
ario:
1. Create an Expression transformation and drag all the ports from the Source Quali-
fier transformation to Expression transformation.
2. Create an
EMPLOYEE_ID
input port in the Lookup transformation that will accept
the value of
EMPLOYEE_ID
using the
:LKP
function.
3. Create another
AGE
output port in the Expression transformation that is used to call
an unconnected Lookup transformation using the
:LKP
function. Link the
AGE
port to the target. Write the
:LKP.LKP_FILE(EMPLOYEE_ID)
function in the
expression editor of the
AGE
column, as shown in the following screenshot:
