UPDATE PREMIER.S_SALES_CENTER
SET CURRENCY_CODE='USD'
WHERE INF_SRC_DB ='AUS'
AND CURRENCY_CODE=  NULL;

CREATE TABLE PREMIER.S_SALES_CENTER
(
  SALES_CENTER_ID         NUMBER(12)            NOT NULL,
  CASH_DISCOUNT           NUMBER(14,2),
  CURRENCY_CODE           VARCHAR2(3 BYTE),
  MASTER_SALES_CENTER_ID  NUMBER(12),
  DISPATCH_PHONE_NUM      VARCHAR2(20 BYTE),
  INF_SRC_DB              VARCHAR2(3 BYTE)      NOT NULL
)

SELECT Count(*) 
FROM   premier.s_sales_center 
WHERE  inf_src_db = 'AUS' 
       AND currency_code = NULL; 

SELECT INF_SRC_DB, Count(*) 
FROM   premier.s_sales_center 
WHERE  currency_code = NULL; 
GROUP BY    inf_src_db
ORDER BY 1

SQL> @ssc
SQL> INSERT INTO S_SALES_CENTER (SALES_CENTER_ID,CURRENCY_CODE, INF_SRC_DB)
  2  VALUES(1,NULL,'AUS');

1 row created.

SQL> INSERT INTO S_SALES_CENTER (SALES_CENTER_ID,CURRENCY_CODE, INF_SRC_DB)
  2  VALUES(2,NULL,'AUS');

1 row created.

SQL> INSERT INTO S_SALES_CENTER (SALES_CENTER_ID,CURRENCY_CODE, INF_SRC_DB)
  2  VALUES(3,NULL,'GER');

1 row created.


  1  UPDATE S_SALES_CENTER
  2  SET CURRENCY_CODE='USD'
  3  WHERE INF_SRC_DB ='AUS'
  4* AND CURRENCY_CODE IS  NULL
SQL> /

2 rows updated.