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The CUSTOMERS table has these columns: CUSTOMER_ID NUMBER(4) NOT NULL CUSTOMER_NAME VARCHAR2(100) NOT NULL STREET_ADDRESS VARCHAR2(150) CITY_ADDRESS VARCHAR2(50) STATE_ADDRESS VARCHAR2(50) PROVINCE_ADDRESS VARCHAR2(50) COUNTRY_ADDRESS VARCHAR2(50) POSTAL_CODE VARCHAR2(12) CUSTOMER_PHONE VARCHAR2(20) The CUSTOMER_ID column is the primary key for the table. Which two statements find the number of customers? （）
A:SELECT TOTAL(*) FROM customer;
B:SELECT COUNT(*) FROM customer;
C:SELECT TOTAL(customer_id) FROM customer;
D:SELECT COUNT(customer_id) FROM customer;
E:SELECT COUNT(customers) FROM customer;
F:SELECT TOTAL(customer_name) FROM customer;

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出自：Oracle认证

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