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 student_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 MODIFY CONSTRAINT stud _ id _pk PRIMARY KEY (student _ id);
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 student_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 MODIFY CONSTRAINT stud _ id _pk PRIMARY KEY (student _ id);
相关考题：
下列说法正确的是()A.alter table user drop column sex;B.alter table user add sex varchar(20);C.alter table user drop sex;D.alter table user modify id int primary key;
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);
Which statement explicitly names a constraint? () A. ALTER TABLE student_grades ADD FOREIGN KEY (student_id) REFERENCES students (student_id);B. ALTER TABLE student_grades ADD CONSTRAINT NAME = student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id);C. ALTER TABLE student_grades ADD CONSTRAINT student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id);D. ALTER TABLE student grades ADD NAMED CONSTRAINT student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id);E. ALTER TABLE student grades ADD NAME student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id);
为表TEST中ID列添加主键约束的语法是（）A、ALTER TABLE TEST CHANGE（ ID INT PRIMARY KEY）B、ALTER TABLE TEST ADD（ ID INT PRIMARY KEY）C、ALTER TABLE TEST MODIFY（ ID INT PRIMARY KEY）D、ALTER TABLE TEST ADD CONSTRAINT PK PRIMARY KEY （ID）
要向雇员表中的部门标识列添加FOREIGNKEY约束条件以引用部门表中的标识列，应该使用哪个语句（）A、ALTER TABLE雇员MODIFY COLUMN dept_id_fk FOREIGN KEY（部门标识）REFERENCES部门（部门标识）B、ALTER TABLE雇员ADD CONSTRAINT dept_id_fk FOREIGNKEY（部门标识）REFERENCES部门（部门标识）C、ALTER TABLE雇员ADD FOREIGN KEY CONSTRAINT dept_id_fk ON（部门标识）REFERENCES部门（部门标识）D、ALTER TABLE雇员ADD FOREIGN KEY 部门（部门标识）REFERENCES（部门标识）
You work in a company which uses SQL Server 2008. You are the administrator of the company database. Now you are in charge of a SQL Server 2008 instance. There is a database named named Dworks in the instance. The Dworks table has a table named BillDetails which has a clustered primary key named BillId on the BillId column. The BillDetails table has a single XML column named GoodsDetails. The XML column has an XML index and XML data are stored in this XML column. A new column named GoodsID is added to the BillDetails table. GoodsID must be included in the primary key. So what action should you perform to achieve this goal？（） A、You should drop the XML index on the table. Modify the primary key. Recreate the XML index B、You should alter the XML index and set the ALLOW_ROW_LOCKS = OFF option. Alter the primary key and set the ALLOW_ROW_LOCKS = ON option. C、You should move the XML data to a temporary table. Clear the XML data from the original table by setting the GoodsDetails column to NULL. Modify the primary key. Repopulate the ProductSpecs column. D、You should disable the XML index on the GoodsDetails column. Modify the primary key.Enable the XML index on the ProductSpecs column.
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.
You need to design a student registration database that contains several tables storing academic information. The STUDENTS table stores information about a student. The STUDENT_GRADES table stores information about the student's grades. Both of the tables have a column named STUDENT_ID. The STUDENT_ID column in the STUDENTS table is a primary key. You need to create a foreign key on the STUDENT_ID column of the STUDENT_GRADES table that points to the STUDENT_ID column of the STUDENTS table. Which statement creates the foreign key?（）A、CREATE TABLE student_grades (student_id NUMBER(12),semester_end DATE, gpa NUMBER(4,3), CONSTRAINT student_id_fk REFERENCES (student_id) FOREIGN KEY student (student_id));B、CREATE TABLE student_grades(student_id NUMBER(12),semester_end DATE, gpa NUMBER(4,3), student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id));C、CREATE TABLE student_grades(student_id NUMBER(12),semester_end DATE, gpa NUMBER(4,3), CONSTRAINT FOREIGN KEY (student_id) REFERENCES student (student_id));D、CREATE TABLE student_grades(student_id NUMBER(12),semester_end DATE, gpa NUMBER(4,3), CONSTRAINT student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id));
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;
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);
User SCOTT wants to back out the transactions on the REGIONS table in his schema. As a DBA， which commands must you execute to enable SCOTT to flash back the transactions？（）A、 ALTER DATABASE FLASHBACK ONB、 GRANT SELECT any transaction TO scottC、 GRANT EXECUTE ON dbms_flashback TO scottD、 ALTER DATABASE ADD SUPPLEMENTAL LOG DATAE、 ALTER TABLESPACE undots1 RETENTION GUARANTEEF、 ALTER DATABASE ADD SUPPLEMENTAL LOG DATA （PRIMARY KEY） COLUMNS
Which statement explicitly names a constraint?（）A、ALTER TABLE student_grades ADD FOREIGN KEY (student_id) REFERENCES students(student_id);B、ALTER TABLE student_grades ADD CONSTRAINT NAME = student_id_fk FOREIGN KEY (student_id) REFERENCES students(student_id);C、ALTER TABLE student_grades ADD CONSTRAINT student_id_fk FOREIGN KEY (student_id) REFERENCES students(student_id);D、ALTER TABLE student grades ADD NAMED CONSTRAINT student_id_fk FOREIGN KEY (student_id) REFERENCES students(student_id);E、ALTER TABLE student grades ADD NAME student_id_fk FOREIGN KEY (student_id) REFERENCES students(student_id);
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);
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 student_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);
Examine the following statement that is used to modify the primary key constraint on the SALES table： SQL ALTER TABLE SALES MODIFY CONSTRAINT pk DISABLE VALIDATE； Which three statements aretrue 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.
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 student_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);
单选题You need to design a student registration database that contains several tables storing academic information. The STUDENTS table stores information about a student. The STUDENT_GRADES table stores information about the student's grades. Both of the tables have a column named STUDENT_ID. The STUDENT_ID column in the STUDENTS table is a primary key. You need to create a foreign key on the STUDENT_ID column of the STUDENT_GRADES table that points to the STUDENT_ID column of the STUDENTS table. Which statement creates the foreign key?（）ACREATE TABLE student_grades (student_id NUMBER(12),semester_end DATE, gpa NUMBER(4,3), CONSTRAINT student_id_fk REFERENCES (student_id) FOREIGN KEY student (student_id));BCREATE TABLE student_grades(student_id NUMBER(12),semester_end DATE, gpa NUMBER(4,3), student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id));CCREATE TABLE student_grades(student_id NUMBER(12),semester_end DATE, gpa NUMBER(4,3), CONSTRAINT FOREIGN KEY (student_id) REFERENCES student (student_id));DCREATE TABLE student_grades(student_id NUMBER(12),semester_end DATE, gpa NUMBER(4,3), CONSTRAINT student_id_fk FOREIGN KEY (student_id) REFERENCES students (student_id));
单选题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?（）AALTER TABLE students ADD PRIMARY KEY _ id;BALTER TABLE students ADD CONSTRAINT PRIMARY KEY (student_id);CALTER TABLE students ADD CONSTRAINT stud_id_pk PRIMARY KEY student_id;DALTER TABLE students ADD CONSTRAINT stud_id_pk PRIMARY KEY (student_id);EALTER TABLE students MODIFY CONSTRAINT stud_id_pk PRIMARY KEY (student_id);
多选题Examine the following statement that is used to modify the primary key constraint on the SALES table： SQL ALTER TABLE SALES MODIFY CONSTRAINT pk DISABLE VALIDATE； Which three statements aretrue regarding the above command（）AThe constraint remains valid.BThe index on the constraint is dropped.CIt allows the loading of data into the table using SQL *Loader.DNew data conforms to the constraint， but existing data is not checked.EIt allows the data manipulation on the table using INSERT/UPDATE/DELETE SQL statements.
单选题Which statement explicitly names a constraint?（）AALTER TABLE student_grades ADD FOREIGN KEY (student_id) REFERENCES students(student_id);BALTER TABLE student_grades ADD CONSTRAINT NAME = student_id_fk FOREIGN KEY (student_id) REFERENCES students(student_id);CALTER TABLE student_grades ADD CONSTRAINT student_id_fk FOREIGN KEY (student_id) REFERENCES students(student_id);DALTER TABLE student grades ADD NAMED CONSTRAINT student_id_fk FOREIGN KEY (student_id) REFERENCES students(student_id);EALTER TABLE student grades ADD NAME student_id_fk FOREIGN KEY (student_id) REFERENCES students(student_id);
单选题You work in a company which uses SQL Server 2008. You are the administrator of the company database. Now you are in charge of a SQL Server 2008 instance. There is a database named named Dworks in the instance. The Dworks table has a table named BillDetails which has a clustered primary key named BillId on the BillId column. The BillDetails table has a single XML column named GoodsDetails. The XML column has an XML index and XML data are stored in this XML column. A new column named GoodsID is added to the BillDetails table. GoodsID must be included in the primary key. So what action should you perform to achieve this goal？（）AYou should drop the XML index on the table. Modify the primary key. Recreate the XML index BYou should alter the XML index and set the ALLOW_ROW_LOCKS = OFF option. Alter the primary key and set the ALLOW_ROW_LOCKS = ON option. CYou should move the XML data to a temporary table. Clear the XML data from the original table by setting the GoodsDetails column to NULL. Modify the primary key. Repopulate the ProductSpecs column. DYou should disable the XML index on the GoodsDetails column. Modify the primary key.Enable the XML index on the ProductSpecs column.
单选题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?（）AALTER TABLE students ADD PRIMARY KEY _ id;BALTER TABLE students ADD CONSTRAINT PRIMARY KEY (student_id);CALTER TABLE students ADD CONSTRAINT stud_id_pk PRIMARY KEY student_id;DALTER TABLE students ADD CONSTRAINT stud_id_pk PRIMARY KEY (student_id);EALTER TABLE students MODIFY CONSTRAINT stud_id_pk PRIMARY KEY (student_id);
单选题View the Exhibit and examine the structure of the EMP table. You executed the following command to add a primary key to the EMP table： ALTER TABLE emp ADD CONSTRAINT emp_id_pk PRIMARY KEY （emp_id） USING INDEX emp_id_idx； Which statement is true regarding the effect of the command？（）A The PRIMARY KEY is created along with a new index.B The PRIMARY KEY is created and it would use an existing unique index.C The PRIMARY KEY would be created in a disabled state because it is using an existing index.D The statement produces an error because the USING clause is permitted only in the CREATE TABLE command.
多选题Which two statements are true about the primary key constraint in a table？ （）AIt is not possible to disable the primary key constraint.BIt is possible to have more than one primary key constraint in a single table.CThe primary key constraint can be referred by only one foreign key constraint.DThe primary key constraint can be imposed by combining more than one column.EThe non-deferrable primary key constraint creates an unique index on the primary key column if it is not already indexed.
单选题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?（）AALTER TABLE students ADD PRIMARY KEY student_id;BALTER TABLE students ADD CONSTRAINT PRIMARY KEY (student _ id);CALTER TABLE students ADD CONSTRAINT stud _ id _pk PRIMARY KEY (student _ id);DALTER TABLE students MODIFY CONSTRAINT stud _ id _pk PRIMARY KEY (student _ id);
单选题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?（）AALTER TABLE students ADD PRIMARY KEY student_id;BALTER TABLE students ADD CONSTRAINT PRIMARY KEY (student_id);CALTER TABLE students ADD CONSTRAINT stud_id_pk PRIMARY KEY student_id;DALTER TABLE students ADD CONSTRAINT stud_id_pk PRIMARY KEY (student_id);EALTER TABLE students MODIFY CONSTRAINT stud_id_pk PRIMARY KEY (student_id);
单选题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?（）AALTER TABLE students ADD PRIMARY KEY student_id;BALTER TABLE students ADD CONSTRAINT PRIMARY KEY (student_id);CALTER TABLE students ADD CONSTRAINT stud_id_pk PRIMARY KEY student_id;DALTER TABLE students ADD CONSTRAINT stud_id_pk PRIMARY KEY (student_id);EALTER TABLE students MODIFY CONSTRAINT stud_id_pk PRIMARY KEY (student_id);