单项选择题
What is true about sequences? （）
A. The start value of the sequence is always 1.
B. A sequence always increments by 1.
C. The minimum value of an ascending sequence defaults to 1.
D. The maximum value of descending sequence defaults to 1.
相关考题
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单项选择题
Examine the structure of the EMPLOYEES table: EMPLOYEE_ID NUMBER Primary Key FIRST_NAME VARCHAR2 (25) LAST_NAME VARCHAR2 (25) HIRE_DATE DATE Which UPDATE statement is valid? （）
A. UPDATE employees SET first_name = 'John' SET last_name = 'Smith' WHERE employee_id = 180;
B. UPDATE employees SET first_name = 'John', SET last_name = 'Smoth' WHERE employee_id = 180;
C. UPDATE employee SET first_name = 'John' AND last_name = 'Smith' WHERE employee_id = 180;
D. UPDATE employee SET first_name = 'John', last_name = 'Smith' WHERE employee_id = 180; -
单项选择题
Examine the statement: Create synonym emp for hr. employees; What happens when you issue the statement? （）
A. An error is generated.
B. You will have two identical tables in the HR schema with different names.
C. You create a table called employees in the HR schema based on you EMP table.
D. You create an alternative name for the employees table in the HR schema in your own schema. -
单项选择题
Which statement accomplish this? （）
A. CREATE TABLE orders ( order_id NUMBER (10), customer_id NUMBER (8), order_status VARCHAR2 (10), date_ordered DATE = SYSDATE);
B. CREATE TABLE orders ( order_id NUMBER (10), customer_id NUMBER (8), order_status VARCHAR2 (10), date_ordered DATE DEFAULT SYSDATE);
C. CREATE OR REPLACE TABLE orders ( order_id NUMBER (10), customer_id NUMBER (8), order_status VARCHAR2 (10), date_ordered DATE DEFAULT SYSDATE);
D. CREATE OR REPLACE TABLE orders ( order_id NUMBER (10), customer_id NUMBER (8), order_status NUMBER (10), date_ordered DATE = SYSDATE);
E. CREATE TABLE orders ( order_id NUMBER (10), customer_id NUMBER (8), order_status NUMBER (10), date_ordered DATE = SYSDATE);
F. CREATE TABLE orders ( order_id NUMBER (10), customer_id NUMBER (8), order_status NUMBER (10), date_ordered DATE DEFAULT SYSDATE);
