(SELECT DISTINCT
   V1.FORPDM_ID AS HVID,
   1 AS IMPORT_STATUS,
   V1.CREATEDAT AS IMPORT_DATE,
   'ok' AS IMPORT_MESSAGE,
   V1.ID AS AT_ID,
   V1.FORPDM_TRANSACTION_ID AS TRANSACTION_ID
 FROM V_VALIDATIONCARRIER V1, V_FORPDM_DAVE_HWDEMAND V2
 WHERE
   V1.FORPDM_ID = V2.HVID AND -- JOIN CONDITION
   ...other conditions...
)

UNION ALL

(SELECT DISTINCT
   V1.FORPDM_ID AS HVID,
   0 AS IMPORT_STATUS,
   V1.CREATEDAT AS IMPORT_DATE,
   'PC_ID is null or not in V_PLANNINGCATEGORY' AS IMPORT_MESSAGE,
   V1.ID AS AT_ID,
   V1.FORPDM_TRANSACTION_ID AS TRANSACTION_ID
 FROM V_VALIDATIONCARRIER V1, V_FORPDM_DAVE_HWDEMAND V2
 WHERE (V1.FORPDM_ID = V2.HVID) AND -- JOIN CONDITION
     ...some error conditions...
)

UNION ALL

(SELECT DISTINCT
   V1.FORPDM_ID AS HVID,
   0 AS IMPORT_STATUS,
   V1.CREATEDAT AS IMPORT_DATE,
   'BAUPHASE is null or not in V_SPEEDSPECIFICMASTERDATA' AS IMPORT_MESSAGE,
   V1.ID AS AT_ID,
   V1.FORPDM_TRANSACTION_ID AS TRANSACTION_ID
 FROM V_VALIDATIONCARRIER V1, V_FORPDM_DAVE_HWDEMAND V2
 WHERE (V1.FORPDM_ID = V2.HVID) AND -- JOIN CONDITION
       ...some other error conditions...
)