多项选择题
The CUSTOMERS table has these columns:
The CUSTOMER_ID column is the primary key for the table.Which two statements find the number of customers? （）
A. SELECT TOTAL(*) FROM customers;
B. SELECT COUNT(*) FROM customers;
C. SELECT TOTAL(customer_id) FROM customers;
D. SELECT COUNT(customer_id) FROM customers;
E. SELECT COUNT(customers) FROM customers;
F. SELECT TOTAL(customer_name) FROM customers;
相关考题
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单项选择题
Examine the description of the EMPLOYEES table: EMP_ID NUMBER(4) NOT NULL LAST_NAME VARCHAR2(30) NOT NULL FIRST_NAME VARCHAR2(30) DEPT_ID NUMBER(2) Which statement produces the number of different departments that have employees with last name Smith?（）
A. SELECT COUNT (*) FROM employees WHERE last _name='smith';
B. SELECT COUNT (dept_id) FROM employees WHERE last _name='smith';
C. SELECT DISTINCT (COUNT (dept_id) FROM employees WHERE last _name='smith';
D. SELECT COUNT (DISTINCT dept_id) FROM employees WHERE last _name='smith';
E. SELECT UNIQE (dept_id) FROM employees WHERE last _name='smith'; -
单项选择题
Which is an iSQL*Plus command?（）
A. INSERT
B. UPDATE
C. SELECT
D. DESCRIBE
E. DELETE
F. RENAME -
单项选择题
Which SQL statement would you use to remove a view called EMP_DEPT_VU from your schema?（）
A. DROP emp_dept_uv;
B. DELETE emp_dept_uv;
C. REMOVE emp_dept_uv;
D. DROP VIEW emp_dept_uv;
E. DELETE VIEW emp_dept_uv;
F. REMOVE VIEW emp_dept_uv;
