Question

suppose I have the following source table (called S):

name   gender code

Bob         0          
Nancy       1          
Ruth        1          
David       0          

And let assume I also have a lookup table (called S_gender_values):

Gender_Code Gender_value

0           Male           
1           Female 

My goal is to create a target table (lets call it T) which will look like this:

name   Gender_Code    

Bob     M             
Nancy   F             
Ruth    F             
David   M             

I also assume that I have a lookup table for table T, called T_GenderValues, which I can use in order to create table T (and validate its results)

Gender_Code    Gender_value   

M                Male          
F                Female        

I thought about 2 (or 3) alternatives:

1. create a mapping table (lets call it S_T_Gender_Code_Mapping) which will look like this:

   S_Gender_Code     T_Gender_code     
   
   0                   M               
   1                   F    
   

   and then do a simple join/lookup using tMap.

2. use tMap and add expression which will implement the mapping, something like:

   (S.Gender_Code==0)?"F":"M"
   

3. similar to Alternative 2 but to use user Java routines.

Is there an other alternative? I hoped I could leverage the ease of tMap to map between S_GenderValues and T_GenderValues and to benefit from the usability of UI tool like we have in tMap

Any hint?

Answer 1

To me, it seems option #1 is needlessly complex and could slow the process. Sure, if you had dozens or thousands of lookups, that’s what you’d want, but not for two.

And option #3 is also too much, as you’re going to want to merge the value into a flow or iterate stream anyway (components like tJavaRow are there to make more complex transformations).

The tMap component can do the simple one-line Java right in the flow, so option 2 sounds to me like your best choice.