单项选择题
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?（）
单项选择题 The EMPLOYEES table has these columns: Management wants to add a default value to the SALARY column. You plan to alter the table by using this SQL statement: What is true about your ALTER statement?（）
多项选择题 Exhibit The COMMISSION column shows the monthly commission earned by the employee. Which two tasks would require subqueries or joins in order to be performed in a single step? （）