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SQL> desc user_order;
Name                                      Null?    Type
----------------------------------------- -------- ----------------------------
REGION_ID                                          NUMBER(2)
CUSTOMER_ID                                        NUMBER(2)
CUSTOMER_SALES                                     NUMBER
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SQL> select * from user_order order by customer_sales;
REGION_ID CUSTOMER_ID CUSTOMER_SALES
---------- ----------- --------------
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        10          29             903383
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