單項選擇題

What is true about updates through a view?（）

A.You cannot update a view with group functions.
B.When you update a view group functions are automatically computed.
C.When you update a view only the constraints on the underlying table will be in effect.
D.When you update a view the constraints on the views always override the constraints on the underlying tables.

你可能感興趣的試題

單項選擇題

Click the Exhibit button and examine the data from the ORDERS and CUSTOMERS tables.
Evaluate the SQL statement:
SELECT *
FROM orders
WHERE cust_id = (SELECT cust_id
FROM customers
WHERE cust_name = 'Smith');
What is the result when the query is executed?（）

A.A
B.B
C.C
D.D
E.E

單項選擇題

The EMP table contains these columns:
EMPLOYEE_ID NUMBER(4)
EMPNAME VARCHAR2 (25)
SALARY NUMBER(9,2)
HIRE_DATE DATE
You query the database with this SQL statement:
SELECT empname,hire_date HIREDATE, salary
FROM EMP
ORDER BY hire_date;
How will the results be sorted?（）

A.randomly
B.ascending by date
C.descending by date
D.ascending alphabetically
E.descending alphabetically

What is true about updates through a view?（）

你可能感興趣的試題

Click the Exhibit button and examine the data from the ORDERS and CUSTOMERS tables. Evaluate the SQL statement: SELECT * FROM orders WHERE cust_id = (SELECT cust_id FROM customers WHERE cust_name = 'Smith'); What is the result when the query is executed?（）

The EMP table contains these columns: EMPLOYEE_ID NUMBER(4) EMPNAME VARCHAR2 (25) SALARY NUMBER(9,2) HIRE_DATE DATE You query the database with this SQL statement: SELECT empname,hire_date HIREDATE, salary FROM EMP ORDER BY hire_date; How will the results be sorted?（）

Click the Exhibit button and examine the data from the ORDERS and CUSTOMERS tables.
Evaluate the SQL statement:
SELECT *
FROM orders
WHERE cust_id = (SELECT cust_id
FROM customers
WHERE cust_name = 'Smith');
What is the result when the query is executed?（）

The EMP table contains these columns:
EMPLOYEE_ID NUMBER(4)
EMPNAME VARCHAR2 (25)
SALARY NUMBER(9,2)
HIRE_DATE DATE
You query the database with this SQL statement:
SELECT empname,hire_date HIREDATE, salary
FROM EMP
ORDER BY hire_date;
How will the results be sorted?（）