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 tru

题目
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.

相似考题

1.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);

2.某数据库系统中，假设有部门关系 Dept (部门号，部门名，负责人，电话)，其中， "部门号"是该关系的主键；员工关系 Emp (员工号，姓名，部门，家庭住址)，属性"家 庭住址"包含省、市、街道以及门牌号，该属性是一个（ ）属性。 创建 Emp 关系的 SQL 语句如下: CREATE TABLE Emp( 员工号 CHAR(4) （ ）， 姓名 CHAR(10)， 部门 CHAR(4)， 家庭住址 CHAR(30)， （ ）; 为在员工关系 Emp 中增加一个"工资"字段，其数据类型为数字型并保留2 位小数， 可采用的 SQL 语句为（ ）。A. 简单 B. 复合 C.多值 D. 派生A. PRIMARY KEY B. NULL C. FOREIGN KEY D. NOT NULLA.PRIMARY KEY NOT NULLB. PRIMARY KEY UNIQUEC. FOREIGN KEY REFERENCES Dept(部门名)D. FOREIGN KEY REFERENCES Dept(部门号)A.ALTER TABLE Emp ADD 工资 CHAR(6,2);B.UPDATA TABLE Emp ADD 工资 NUMERIC(6，2);C.ALTER TABLE Emp ADD 工资 NUMERIC （6,2）;D.ALTER TABLE Emp MODIFY 工资 NUMERI C(6,2);

3.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）

4.Given the following requirements:Create a table to contain employee data, with a unique numeric identifier automatically assigned when a row is added, has an EDLEVEL column that permits only the values ‘C‘, ‘H‘ and ‘N‘, and permits inserts only when a corresponding value for the employee‘s department exists in the DEPARTMENT table.Which of the following CREATE statements will successfully create this table?（）A.CREATE TABLE emp ( empno SMALLINT NEXTVAL GENERATED ALWAYS AS IDENTITY, firstname VARCHAR(30) NOT NULL, lastname VARCHAR(30) NOT NULL, workdept CHAR(3) NOT NULL, edlevel CHAR(1), PRIMARY KEY emp_pk (empno), FOREIGN KEY emp_workdept_fk ON (workdept) REFERENCES department (deptno), CHECK edlevel_ck VALUES (edlevel IN (‘C‘,‘H‘,‘N‘)), );B.CREATE TABLE emp ( empno SMALLINT NOT NULL GENERATED BY DEFAULT AS IDENTITY, firstname VARCHAR(30) NOT NULL, lastname VARCHAR(30) NOT NULL, workdept CHAR(3), edlevel CHAR(1), CONSTRAINT emp_pk PRIMARY KEY (empno), CONSTRAINT emp_workdept_fk FOREIGN KEY (workdept) REFERENCES department (deptno), CONSTRAINT edlevel_ck CHECK edlevel VALUES (‘C‘,‘H‘,‘N‘) );C.CREATE TABLE emp ( empno SMALLINT NEXTVAL GENERATED BY DEFAULT AS IDENTITY, firstname VARCHAR(30) NOT NULL, lastname VARCHAR(30) NOT NULL, workdept CHAR(3) NOT NULL, edlevel CHAR(1) CHECK IN (‘C‘,‘H‘,‘N‘)), CONSTRAINT emp_pk PRIMARY KEY (empno), CONSTRAINT emp_workdept_fk FOREIGN KEY department (deptno) REFERENCES (workdept) );D.CREATE TABLE emp ( empno SMALLINT NOT NULL GENERATED BY DEFAULT AS IDENTITY, firstname VARCHAR(30) NOT NULL, lastname VARCHAR(30) NOT NULL, workdept CHAR(3), edlevel CHAR(1), CONSTRAINT emp_pk PRIMARY KEY (empno), CONSTRAINT emp_workdept_fk FOREIGN KEY (workdept) REFERENCES department (deptno), CONSTRAINT edlevel_ck CHECK (edlevel IN (‘C‘,‘H‘,‘N‘)) );

更多“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 tru”相关问题

  • 第1题：

    Given the following requirements: Create a table to contain employee data, with a unique numeric identifier automatically assigned when a row is added, has an EDLEVEL column that permits only the values 'C', 'H' and 'N', and permits inserts only when a corresponding value for the employee's department exists in the DEPARTMENT table. Which of the following CREATE statements will successfully create this table?（）

    • A、CREATE TABLE emp ( empno SMALLINT NEXTVAL GENERATED ALWAYS AS IDENTITY, firstname VARCHAR(30) NOT NULL, lastname VARCHAR(30) NOT NULL, workdept CHAR(3) NOT NULL, edlevel CHAR(1), PRIMARY KEY emp_pk (empno), FOREIGN KEY emp_workdept_fk ON (workdept) REFERENCES department (deptno), CHECK edlevel_ck VALUES (edlevel IN ('C','H','N')), );
    • B、CREATE TABLE emp ( empno SMALLINT NOT NULL GENERATED BY DEFAULT AS IDENTITY, firstname VARCHAR(30) NOT NULL, lastname VARCHAR(30) NOT NULL, workdept CHAR(3), edlevel CHAR(1), CONSTRAINT emp_pk PRIMARY KEY (empno), CONSTRAINT emp_workdept_fk FOREIGN KEY (workdept) REFERENCES department (deptno), CONSTRAINT edlevel_ck CHECK edlevel VALUES ('C','H','N') );
    • C、CREATE TABLE emp ( empno SMALLINT NEXTVAL GENERATED BY DEFAULT AS IDENTITY, firstname VARCHAR(30) NOT NULL, lastname VARCHAR(30) NOT NULL, workdept CHAR(3) NOT NULL, edlevel CHAR(1) CHECK IN ('C','H','N')), CONSTRAINT emp_pk PRIMARY KEY (empno), CONSTRAINT emp_workdept_fk FOREIGN KEY department (deptno) REFERENCES (workdept) );
    • D、CREATE TABLE emp ( empno SMALLINT NOT NULL GENERATED BY DEFAULT AS IDENTITY, firstname VARCHAR(30) NOT NULL, lastname VARCHAR(30) NOT NULL, workdept CHAR(3), edlevel CHAR(1), CONSTRAINT emp_pk PRIMARY KEY (empno), CONSTRAINT emp_workdept_fk FOREIGN KEY (workdept) REFERENCES department (deptno), CONSTRAINT edlevel_ck CHECK (edlevel IN ('C','H','N')) );

    正确答案:D

  • 第2题：

    You executed the following FLASHBACK TABLE command： FLASHBACK TABLE emp TO TIMESTAMP （’11：45’，’hh12：mi’）; Which two statements are correct？（）

    • A、The FLASHBACK TABLE statement will not be written to the alert log file.
    • B、The changes made to the EMP table since the specified time will be undone.
    • C、The EMP table that was dropped by mistake from the database will be restored.
    • D、The FLASHBACK TABLE statement will be executed within a single transaction.
    • E、The FLASHBACK TABLE statement will not maintain the existing indexes on the EMP table. 
    • F、The list of transactions that have modified the EMP table since the specified time will be displayed.

    正确答案:B,D

  • 第3题：

    The EMPLOYEES table is stored in the SAMPLE tablespace.  The corresponding IPK_EMP index for the EMPLOYEES table’s primary key is stored in the INDX tablespace.  Out of 12 partitions， only partition P1 of the SALES table is stored in the SAMPLE tablespace.  Which object will be exported by this command？（）   exp system/manager tablespaces=SAMPLE

    • A、Only the EMPLOYEES table.
    • B、Only the EMPLOYEES table and its corresponding primary key index.
    • C、The EMPLOYEES table and partition P1.
    • D、The EMPLOYEES table， IPK_EMP index， and the SALES table.

    正确答案:D

  • 第4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);

    正确答案:D

  • 第5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（）

    • 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.

    正确答案:A,B,C

  • 第6题：

    单选题
    Which SQL statement defines the FOREIGN KEY constraint on the DEPTNO column of the EMP table?（）
    A

    CREATE TABLE EMP (empno NUMBER(4), ename VARCNAR2(35), deptno NUMBER(7,2) NOT NULL CONSTRAINT emp_deptno_fk FOREIGN KEY deptno REFERENCES dept deptno);

    B

    CREATE TABLE EMP (empno NUMBER(4), ename VARCNAR2(35), deptno NUMBER(7,2) CONSTRAINT emp_deptno_fk REFERENCES dept (deptno));

    C

    CREATE TABLE EMP (empno NUMBER(4) ename VARCHAR2(35), deptno NUMBER(7,2) NOT NULL, CONSTRAINT emp_deptno_fk REFERENCES dept (deptno) FOREIGN KEY (deptno));

    D

    CREATE TABLE EMP (empno NUMBER(4), ename VARCNAR2(35), deptno NUMBER(7,2) FOREIGN KEY CONSTRAINT emp deptno fk REFERENCES dept (deptno));


    正确答案： A
    解析： 暂无解析

  • 第7题：

    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（）
    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.


    正确答案： C,B
    解析： 暂无解析

  • 第8题：

    单选题
    The EMPLOYEES table is stored in the SAMPLE tablespace.  The corresponding IPK_EMP index for the EMPLOYEES table’s primary key is stored in the INDX tablespace.  Out of 12 partitions， only partition P1 of the SALES table is stored in the SAMPLE tablespace.  Which object will be exported by this command？（）   exp system/manager tablespaces=SAMPLE
    A

    Only the EMPLOYEES table.

    B

    Only the EMPLOYEES table and its corresponding primary key index.

    C

    The EMPLOYEES table and partition P1.

    D

    The EMPLOYEES table， IPK_EMP index， and the SALES table.


    正确答案： A
    解析： 暂无解析

  • 第9题：

    单选题
    You moved the index EMP_NO_INDX from one tablespace to another and then issued the following command to rebuild the index EMP_NO_INDX：   SQL> ALTER INDEX EMP_NO_INDX REBUILD ONLINE；   Which table allows the users to access the EMP_NO_INDX index while performing the rebuild operation？（）
    A

     Index-organized table

    B

     Mapping Table

    C

     Clustered Table

    D

     Journal Table


    正确答案： C
    解析： 暂无解析

  • 第10题：

    单选题
    Given the following requirements: Create a table to contain employee data, with a unique numeric identifier automatically assigned when a row is added, has an EDLEVEL column that permits only the values 'C', 'H' and 'N', and permits inserts only when a corresponding value for the employee's department exists in the DEPARTMENT table. Which of the following CREATE statements will successfully create this table?（）
    A

    CREATE TABLE emp ( empno SMALLINT NEXTVAL GENERATED ALWAYS AS IDENTITY, firstname VARCHAR(30) NOT NULL, lastname VARCHAR(30) NOT NULL, workdept CHAR(3) NOT NULL, edlevel CHAR(1), PRIMARY KEY emp_pk (empno), FOREIGN KEY emp_workdept_fk ON (workdept) REFERENCES department (deptno), CHECK edlevel_ck VALUES (edlevel IN ('C','H','N')), );

    B

    CREATE TABLE emp ( empno SMALLINT NOT NULL GENERATED BY DEFAULT AS IDENTITY, firstname VARCHAR(30) NOT NULL, lastname VARCHAR(30) NOT NULL, workdept CHAR(3), edlevel CHAR(1), CONSTRAINT emp_pk PRIMARY KEY (empno), CONSTRAINT emp_workdept_fk FOREIGN KEY (workdept) REFERENCES department (deptno), CONSTRAINT edlevel_ck CHECK edlevel VALUES ('C','H','N') );

    C

    CREATE TABLE emp ( empno SMALLINT NEXTVAL GENERATED BY DEFAULT AS IDENTITY, firstname VARCHAR(30) NOT NULL, lastname VARCHAR(30) NOT NULL, workdept CHAR(3) NOT NULL, edlevel CHAR(1) CHECK IN ('C','H','N')), CONSTRAINT emp_pk PRIMARY KEY (empno), CONSTRAINT emp_workdept_fk FOREIGN KEY department (deptno) REFERENCES (workdept) );

    D

    CREATE TABLE emp ( empno SMALLINT NOT NULL GENERATED BY DEFAULT AS IDENTITY, firstname VARCHAR(30) NOT NULL, lastname VARCHAR(30) NOT NULL, workdept CHAR(3), edlevel CHAR(1), CONSTRAINT emp_pk PRIMARY KEY (empno), CONSTRAINT emp_workdept_fk FOREIGN KEY (workdept) REFERENCES department (deptno), CONSTRAINT edlevel_ck CHECK (edlevel IN ('C','H','N')) );


    正确答案： A
    解析： 暂无解析

  • 第11题：

    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?（）
    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);


    正确答案： B
    解析： 暂无解析

  • 第12题：

    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?（）
    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);


    正确答案： E
    解析： 暂无解析

  • 第13题：

    You moved the index EMP_NO_INDX from one tablespace to another and then issued the following command to rebuild the index EMP_NO_INDX：   SQL> ALTER INDEX EMP_NO_INDX REBUILD ONLINE；   Which table allows the users to access the EMP_NO_INDX index while performing the rebuild operation？（） 

    • A、 Index-organized table
    • B、 Mapping Table
    • C、 Clustered Table
    • D、 Journal Table

    正确答案:D

  • 第14题：

    Which SQL statement defines the FOREIGN KEY constraint on the DEPTNO column of the EMP table?（）

    • A、CREATE TABLE EMP (empno NUMBER(4), ename VARCNAR2(35), deptno NUMBER(7,2) NOT NULL CONSTRAINT emp_deptno_fk FOREIGN KEY deptno REFERENCES dept deptno);
    • B、CREATE TABLE EMP (empno NUMBER(4), ename VARCNAR2(35), deptno NUMBER(7,2) CONSTRAINT emp_deptno_fk REFERENCES dept (deptno));
    • C、CREATE TABLE EMP (empno NUMBER(4) ename VARCHAR2(35), deptno NUMBER(7,2) NOT NULL, CONSTRAINT emp_deptno_fk REFERENCES dept (deptno) FOREIGN KEY (deptno));
    • D、CREATE TABLE EMP (empno NUMBER(4), ename VARCNAR2(35), deptno NUMBER(7,2) FOREIGN KEY CONSTRAINT emp deptno fk REFERENCES dept (deptno));

    正确答案:B

  • 第15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 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);

    正确答案:C

  • 第16题：

    Which SQL statement defines a FOREIGN KEY constraint on the DEPTNO column of the EMP table?（）

    • A、CREATE TABLE EMP (empno NUMBER(4), ename VARCHAR2(35), deptno NUMBER(7,2) NOT NULL, CONSTRAINT emp_deptno_fk FOREIGN KEY deptno REFERENCES dept deptno);
    • B、CREATE TABLE EMP (empno NUMBER(4), ename VARCHAR2(35), deptno NUMBER(7,2) CONSTRAINT emp_deptno_fk REFERENCES dept (deptno));
    • C、CREATE TABLE EMP (empno NUMBER(4), ename VARCHAR2(35), deptno NUMBER(7,2) NOT NULL, CONSTRAINT emp_deptno_fk REFERENCES dept (deptno) FOREIGN KEY (deptno));
    • D、CREATE TABLE EMP (empno NUMBER(4), ename VARCHAR2(35), deptno NUMBER(7,2) FOREIGN KEY CONSTRAINT emp_deptno_fk REFERENCES dept (deptno));

    正确答案:B

  • 第17题：

    You executed the following FLASHBACK TABLE command： FLASHBACK TABLE emp TO TIMESTAMP （’11：45’，’hh12：mi’）； Which two statements are correct？ （）

    • A、 The FLASHBACK TABLE statement will not be written to the alert log file.
    • B、 The EMP table that was dropped by mistake from the database will be restored.
    • C、 The changes made to the EMP table since the specified time will be undone.
    • D、 The FLASHBACK TABLE statement will not maintain the existing indexes on the EMP table.
    • E、 The FLASHBACK TABLE statement will be executed within a single transaction.
    • F、 The list of transactions that have modified the EMP table since the specified time will be displayed.

    正确答案:C,E

  • 第18题：

    多选题
    You executed the following FLASHBACK TABLE command： FLASHBACK TABLE emp TO TIMESTAMP （’11：45’，’hh12：mi’）； Which two statements are correct？ （）
    A

    The FLASHBACK TABLE statement will not be written to the alert log file.

    B

    The EMP table that was dropped by mistake from the database will be restored.

    C

    The changes made to the EMP table since the specified time will be undone.

    D

    The FLASHBACK TABLE statement will not maintain the existing indexes on the EMP table.

    E

    The FLASHBACK TABLE statement will be executed within a single transaction.

    F

    The list of transactions that have modified the EMP table since the specified time will be displayed.


    正确答案： D,B
    解析： 暂无解析

  • 第19题：

    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?（）
    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);


    正确答案： D
    解析： 暂无解析

  • 第20题：

    单选题
    Which SQL statement defines a FOREIGN KEY constraint on the DEPTNO column of the EMP table?（）
    A

    CREATE TABLE EMP (empno NUMBER(4), ename VARCHAR2(35), deptno NUMBER(7,2) NOT NULL, CONSTRAINT emp_deptno_fk FOREIGN KEY deptno REFERENCES dept deptno);

    B

    CREATE TABLE EMP (empno NUMBER(4), ename VARCHAR2(35), deptno NUMBER(7,2) CONSTRAINT emp_deptno_fk REFERENCES dept (deptno));

    C

    CREATE TABLE EMP (empno NUMBER(4), ename VARCHAR2(35), deptno NUMBER(7,2) NOT NULL, CONSTRAINT emp_deptno_fk REFERENCES dept (deptno) FOREIGN KEY (deptno));

    D

    CREATE TABLE EMP (empno NUMBER(4), ename VARCHAR2(35), deptno NUMBER(7,2) FOREIGN KEY CONSTRAINT emp_deptno_fk REFERENCES dept (deptno));


    正确答案： A
    解析： 暂无解析

  • 第21题：

    多选题
    Examine the structure of the EMPLOYEES table: EMPLOYEE_ID NUMBER NOT NULL, Primary Key EMP_NAME VARCHAR2(30) JOB_ID NUMBER SAL NUMBER MGR_ID NUMBER References EMPLOYEE_ID column DEPARTMENT_ID NUMBER Foreign key to DEPARTMENT_ID column of the DEPARTMENTS table You created a sequence called EMP_ID_SEQ in order to populate sequential values for the EMPLOYEE_ID column of the EMPLOYEES table. Which two statements regarding the EMP_ID_SEQ sequence are true? （）
    A

    You cannot use the EMP_ID_SEQ sequence to populate the JOB_ID column.

    B

    The EMP_ID_SEQ sequence is invalidated when you modify the EMPLOYEE_ID column.

    C

    The EMP_ID_SEQ sequence is not affected by modifications to the EMPLOYEES table.

    D

    Any other column of NUMBER data type in your schema can use the EMP_ID_SEQ sequence.

    E

    The EMP_ID_SEQ sequence is dropped automatically when you drop the EMPLOYEES table.

    F

    The EMP_ID_SEQ sequence is dropped automatically when you drop the EMPLOYEE_ID column.


    正确答案： C,B
    解析： 暂无解析

  • 第22题：

    单选题
    Given the following requirements: Create a table to contain employee data, with a unique numeric identifier automatically assigned when a row is added, has an EDLEVEL column that permits only the values 'C', 'H' and 'N', and permits inserts only when a corresponding value for the employee's department exists in the DEPARTMENT table. Which of the following CREATE statements will successfully create this table?（）
    A

    CREATE TABLE emp ( empno SMALLINT NEXTVAL GENERATED ALWAYS AS IDENTITY, firstname VARCHAR(30) NOT NULL, lastname VARCHAR(30) NOT NULL, workdept CHAR(3) NOT NULL, edlevel CHAR(1), PRIMARY KEY emp_pk (empno), FOREIGN KEY emp_workdept_fk ON (workdept) REFERENCES department (deptno), CHECK edlevel_ck VALUES (edlevel IN ('C','H','N')), );

    B

    CREATE TABLE emp ( empno SMALLINT NOT NULL GENERATED BY DEFAULT AS IDENTITY, firstname VARCHAR(30) NOT NULL, lastname VARCHAR(30) NOT NULL, workdept CHAR(3), edlevel CHAR(1), CONSTRAINT emp_pk PRIMARY KEY (empno), CONSTRAINT emp_workdept_fk FOREIGN KEY (workdept) REFERENCES department (deptno), CONSTRAINT edlevel_ck CHECK edlevel VALUES ('C','H','N') );

    C

    CREATE TABLE emp ( empno SMALLINT NEXTVAL GENERATED BY DEFAULT AS IDENTITY, firstname VARCHAR(30) NOT NULL, lastname VARCHAR(30) NOT NULL, workdept CHAR(3) NOT NULL, edlevel CHAR(1) CHECK IN ('C','H','N')), CONSTRAINT emp_pk PRIMARY KEY (empno), CONSTRAINT emp_workdept_fk FOREIGN KEY department (deptno) REFERENCES (workdept) );

    D

    CREATE TABLE emp ( empno SMALLINT NOT NULL GENERATED BY DEFAULT AS IDENTITY, firstname VARCHAR(30) NOT NULL, lastname VARCHAR(30) NOT NULL, workdept CHAR(3), edlevel CHAR(1), CONSTRAINT emp_pk PRIMARY KEY (empno), CONSTRAINT emp_workdept_fk FOREIGN KEY (workdept) REFERENCES department (deptno), CONSTRAINT edlevel_ck CHECK (edlevel IN ('C','H','N')) );


    正确答案： C
    解析： 暂无解析

  • 第23题：

    单选题
    EXHIBIT, Emp Table Exhibit A Exhibit B Examine the data from the EMP table. Evaluate this SQL statement: SELECT * FROM emp WHERE emp _ id = 3); WHERE commission = (SELECT commission FROM emp What is the result when the query is executed?（）
    A

    Exhibit A

    B

    Exhibit B 

    C

    The query returns no rows 

    D

    The query fails because the outer query is retrieving more than one column

    E

    The query fails because both the inner and outer queries are retrieving data from the same table.


    正确答案： C
    解析： 暂无解析

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