Examine the following statement that is used to modify the constraint on the SALES table： SQL> ALTER TABLE SALES MODIFY CONSTRAINT pk DISABLE VALIDATE； Which three statements are true regarding the above command（）A、The constraint remains valid.B、The inde

题目

Examine the following statement that is used to modify the constraint on the SALES table： SQL> ALTER TABLE SALES MODIFY CONSTRAINT pk DISABLE VALIDATE； Which three statements are true regarding the above command（）

A、The constraint remains valid.
B、The index on the constraint is dropped.
C、It allows the loading of data into the table using SQL*Loader.
D、New data conforms to the constraint， but existing data is not checked
E、It allows the data manipulation on the table using INSERT/UPDATE/DELETE SQL statements.

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相似问题和答案

第1题：

删除PRIMARYKEY约束条件及其所有依赖约束条件的语法是什么（）

A、ALTER TABLE table_name DROP CONSTRAINT constraint_name CASCADE
B、ALTER TABLE table_name DROP CONSTRAINT FOREIGN KEY CASCADE
C、DROP CONSTRAINT table_name（constraint_name）
D、ALTER TABLE table_name DROP CONSTRAINT constraint_name

正确答案:A

第2题：

A constraint in a table is defined with the INITIALLY IMMEDIATE clause. You executed the ALTER TABLEcommand with the ENABLE VALIDATE option to enable the constraint that was disabled. What are the twoeffects of this command（）

A、It fails if any existing row violates the constraint.
B、It does not validate the existing data in the table.
C、It enables the constraint to be enforced at the end of each transaction.
D、It prevents insert， update， and delete operations on the table while the constraint is in the process of beingenabled

正确答案:A,D

第3题：

You need to modify the STUDENTS table to add a primary key on the STUDENT_ID column. The table is currently empty. Which statement accomplishes this task?()

A. ALTER TABLE students ADD PRIMARY KEY _ id;

B. ALTER TABLE students ADD CONSTRAINT PRIMARY KEY (student_id);

C. ALTER TABLE students ADD CONSTRAINT stud_id_pk PRIMARY KEY student_id;

D. ALTER TABLE students ADD CONSTRAINT stud_id_pk PRIMARY KEY (student_id);

E. ALTER TABLE students MODIFY CONSTRAINT stud_id_pk PRIMARY KEY (student_id);

参考答案：D

第4题：

You just issued the following statement: ALTER TABLE SALES DROP COLUMN PROFIT. Which of the following choices identifies when the column will actually be removed from Oracle?（）

A、Immediately following statement execution
B、After the ALTER TABLE DROP UNUSED COLUMNS command is issued
C、After the ALTER TABLE SET UNUSED COLUMN command is issued
D、After the ALTER TABLE MODIFY command is issued

正确答案:B

第5题：

Which two statements are true about the primary key constraint in a table？（）

A、It is not possible to disable the primary key constraint.
B、It is possible to have more than one primary key constraint in a single table.
C、The primary key constraint can be referred by only one foreign key constraint.
D、The primary key constraint can be imposed by combining more than one column.
E、The non-deferrable primary key constraint creates an unique index on the primary key column if it is not already indexed.

正确答案:D,E

第6题：

Which syntax turns an existing constraint on?（）

A、ALTER TABLE table_name ENABLE constraint_name;
B、ALTER TABLE table_name STATUS = ENABLE CONSTRAINT constraint_name;
C、ALTER TABLE table_name ENABLE CONSTRAINT constraint_name;
D、ALTER TABLE table_name STATUS ENABLE CONSTRAINT constraint_name;
E、ALTER TABLE table_name TURN ON CONSTRAINT constraint_name;

正确答案:C

第7题：

Evaluate the CREATE TABLE statement： CREATE TABLE products （product_id NUMBER （6） CONSTRAINT prod_id_pk PRIMARY KEY， product_name VARCHAR2 （15））； Which statement is true regarding the PROD_ID_PK constraint？（）

A、 It would be created only if a unique index is manually created first.
B、 It would be created and would use an automatically created unique index.
C、 It would be created and would use an automatically created nonunique index.
D、 It would be created and remains in a disabled state because no index is specified in the command.

正确答案:B

第8题：

Which syntax turns an existing constraint on? ()

A. ALTER TABLE table_name ENABLE constraint_name;

B. ALTER TABLE table_name STATUS = ENABLE CONSTRAINT constraint _ name;

C. ALTER TABLE table_name ENABLE CONSTRAINT constraint _ name;

D. ALTER TABLE table_name TURN ON CONSTRAINT constraint _ name;

参考答案：C

第9题：

Which syntax turns an existing constraint on?（）

A、ALTER TABLE table_name ENABLE constraint_name;
B、ALTER TABLE table_name STATUS = ENABLE CONSTRAINT constraint _ name;
C、ALTER TABLE table_name ENABLE CONSTRAINT constraint _ name;
D、ALTER TABLE table_name TURN ON CONSTRAINT constraint _ name;

正确答案:C

第10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;

正确答案:C

Examine the following statement that is used to modify the constraint on the SALES table： SQL ALTER TABLE SALES MODIFY CONSTRAINT pk DISABLE VALIDATE； Which three statements are true regarding the above command（）A、The constraint remains valid.B、The index

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