Modify Key Field Values of a table through Table Maintenance Generator

Question

Hi All,
   I have created a z table with below structure. In this fields upto Valid To are all key fields. This is to ensure that consistant valid record get stored in the table.
MANDT     MANDT     CLNT     3     0     Client
VKORG     VKORG     CHAR     4     0     Sales Organization
VTWEG     VTWEG     CHAR     2     0     Distribution Channel
SPART     SPART     CHAR     2     0     Division
SKU     MATNR     CHAR     18     0     Material Number
LZONE     LZONE     CHAR     10     0     Transportation zone to or from which the goods are delivered
VALID_FROM     ZVALID_FROM     DATS     8     0     Valid From
VALID_TO     ZVALID_TO     DATS     8     0     Valid To
PLANT     WERKS_D     CHAR     4     0     Plant
SNP_TZONE     ZSNP_TZONE     CHAR     20     0     APO Transportation Zone
ERDAT     ERDAT     DATS     8     0     Date on Which Record Was Created
ERNAM     ERNAM     CHAR     12     0     Name of Person who Created the Object
AEDAT     AEDAT     DATS     8     0     Changed On
AENAME     AENAME     CHAR     12     0     Last changed by
I have created a Table Maintance program through the Table Maintenance Generator. And for that I have assigned a t code.
I can able to create new entires but i can not able to modify Valid_from and Valid_to entries of existing records.
Initially those two fields were in display mode but i went to its module pool program and made then as input enabled. But what the vales I was entering, its not getting saved in database. When we change the values of those fields and save it, the system is saying No Data Change.
Any inputs how to solve this issue. I can not make VALID_FROM and VALID_TO fields as non key.
Regards,

Answer 1

Hi,
  As you have already said that the value for valid to is a part of the key so you should not have any issues when this value is changed and the value is saved using the table maintainence generator, but in case you want to save values where the value for valid from has changed but the key is same we would not be able to save as there is already a value for the key, so if you want to save these values there are two ways 1 would either to delete the existing value value and create the new value or to have one more field as the key field like a counter so when the value is saved with a key the value is saved with counter as 1 and then ever next time for the new values increase the value of the counter.
In order to save these values use event 5 and put you code there.
You can also carry out checks for new aithorization in that event also.
Regards,
Himanshu