IF NOT EXISTS (SELECT 1 FROM KSQL_USERCOLUMNS WHERE KSQL_COL_TABNAME = 'T_IM_PURRECBILLENTRY_R' AND KSQL_COL_NAME IN ('FPURORDERBILLNUMBER')) 
 ALTER TABLE T_IM_PURRECBILLENTRY_D ADD (FPURORDERBILLNUMBER NVARCHAR(80) DEFAULT ' ' NOT NULL );