多项选择题
A.A WHERE clause can be used to restrict both rows and groups.
B.A WHERE clause can be used to restrict rows only.
C.A HAVING clause can be used to restrict both rows and groups.
D.A HAVING clause can be used to restrict groups only.
E.A WHERE clause CANNOT be used in a query if the query uses a HAVING clause.
F.A HAVING clause CANNOT be used in subqueries.
多项选择题 In which two cases would you use an outer join? （）
单项选择题 You need to create a table named ORDERS that contains four columns: 1.an ORDER_ID column of number data type 2.a CUSTOMER_ID column of number data type 3.an ORDER_STATUS column that contains a character data type 4.a DATE_ORDERED column to contain the date the order was placed When a row is inserted into the table, if no value is provided for the status of the order, the value PENDING should be used instead. Which statement accomplishes this?（）
单项选择题 Examine the structure of the EMPLOYEES and NEW_EMPLOYEES tables: EMPLOYEES EMPLOYEE_ID NUMBER Primary Key FIRST_NAME VARCHAR2(25) LAST_NAME VARCHAR2(25) HIRE_DATE DATE NEW_EMPLOYEES EMPLOYEE_ID NUMBER Primary Key NAME VARCHAR2(60) Which DELETE statement is valid?（）