Lookup Table and Target Table are the same

Question

Hi All,
I have a requirement in which I have to lookup the target table and based on the records in it, I need to load a new record into the target table.
Being very specific,
Suppose I have a key column which when changes I want to generate a new id and then insert this new value.
The target table record structure looks like this
list_id list_key list_name
1 'A' 'NAME1'
1 'A' 'NAME2'
1 'A' 'NAME3'
2 'B' 'NAME4'
2 'B' 'NAME5'
As shown the target table list_id changes only when the list key changes. I need to generate the list_id value from within OWB mapping.
Can anyone throw some light as to how this can be done in OWB???
regards
-AP

Answer 1

Hello, AP
You underestimate the power of single mapping :) If you could tolerate using additional stage table (with is definitly recomended in case your table from example will account a lot of rows).
You underestimate the power of single mapping :) It you could tolerate using additional stage table (witch is definitely recommended in case your table from example will account a lot of rows), you could accomplish all you need within one mapping and without using PLSQL function. This is true as far as you could have several targets within one mapping.
Source ----------------------------------------------------- >| Join2 | ---- > Target 2
|------------------------ >|Join 1| --> Lookup table -->|
Target Dedup >|
Here “Target” – your target table. “Join 1“ – operator covers operations needed to get existing key mapping (from dedup) and find new mappings. Results are stored within Lookup Table target (operation type TRUNCATE/INSERT).
“Join 2” is used to perform final lookup and load it into the “Target 2” – the same as “Target”
The approach with lookup table is fast and reliable and could run on Set base mode. Also you could revisit lookup table to find what key mapping are loaded during last load operation.
Serhit