多选题Which four are valid Oracle constraint types? （）ACASCADEBUNIQUECNONUNIQUEDCHECKEPRIMARY KEYFCONSTANTGNOT NULL

第1题：

Which of the following constraint types can be used to ensure the value of an INTEGER column references only positive values?（）

• A、Unique
• B、Check
• C、Referential
• D、Informational

第2题：

Which two statements are true about constraints? （）

• A、The UNIQUE constraint does not permit a null value for the column.
• B、A UNIQUE index gets created for columns with PRIMARY KEY and UNIQUE constraints.
• C、The PRIMARY KEY and FOREIGN KEY constraints create a UNIQUE index.
• D、The NOT NULL constraint ensures that null values are not permitted for the column.

第3题：

第4题：

第5题：

Which statement adds a constraint that ensures the CUSTOMER_NAME column of the CUSTOMERS table holds a value?（）

• A、ALTER TABLE customers ADD CONSTRAINT cust_name_nn CHECK customer_name IS NOT NULL;
• B、ALTER TABLE customers MODIFY CONSTRAINT cust_name_nn CHECK customer_name IS NOT NULL;
• C、ALTER TABLE customers MODIFY customer_name CONSTRAINT cust_name_nn NOT NULL;
• D、ALTER TABLE customers MODIFY customer_name CONSTRAINT cust_name_nn IS NOT NULL;
• E、ALTER TABLE customers MODIFY name CONSTRAINT cust_name_nn NOT NULL;
• F、ALTER TABLE customers ADD CONSTRAINT cust_name_nn CHECK customer_name NOT NULL;

第6题：

Which three message types are valid PIMv2 message types？（）

• A、Register
• B、Register-Stop
• C、Join/Prune
• D、Reject
• E、Register-Prune
• F、Register-Join

第7题：

You executed the following code：   SQL> CERATE TABLE COUNTRY   （COUNTRY_ID CHAR（2） CONSTRAINT COUNTRY_ID_nn NOT NULL，   COUNTRY_NAME VARCHAR2（20），   CURRENCY_NAME VARCHAR2（20），   CONSTRAINT COUNTRY_ID_PK PRIMARY KEY （COUNTRY_ID））   ORGANIZATION INDEX；   Which types of tables will be created automatically？（）

• A、 journal table
• B、 clustered table
• C、 mapping table
• D、 partitioned table

第8题：

第9题：

You need to design the restrictions on the Bank.Customers table. Which three actions should you perform?（）

• A、Design a trigger that verifies that the first names and surnames are not empty strings.
• B、Design a check constraint that verifies that the first names and surnames are not empty strings.
• C、Design a check constraint that uses a CLR user-defined function to verify that either the phone number is a null value or the format of the phone number is valid.
• D、Design a trigger that uses a CLR user-defined function to verify that either the phone number is a null value or the format of the phone number is valid.
• E、Design a check constraint that ensures that the phone number cannot be changed from a valid format to a null value or to an invalid format.
• F、Design a trigger that ensures that the phone number cannot be changed from a valid format to a null value.

第10题：