有如下三步操作,并且均成功执行,请选择结果()delete from emp;alter table emp add(addr varchar2(40));rollback; A. emp表中数据处于回滚段中B. emp表中的数据被永久删除C. emp表中的数据没有变化D. 原来的emp表中的数据被添加到新emp表中E. 以上所述都不正确
有如下三步操作,并且均成功执行,请选择结果()delete from emp;alter table emp add(addr varchar2(40));rollback;
A. emp表中数据处于回滚段中
B. emp表中的数据被永久删除
C. emp表中的数据没有变化
D. 原来的emp表中的数据被添加到新emp表中
E. 以上所述都不正确
相关考题：
以下语句错误的是( )A. alter table emp delete column addcolumn;B. alter table emp modify column addcolumn char(10);C.alter table emp change addcolumn addcolumn int;D. alter table emp add column addcolumn int;
以下删除记录正确的( )A.delete from emp where name='dony';B.Delete * from emp where name='dony';C.Drop from emp where name='dony';D.Drop * from emp where name='dony';
以下能够删除一列的是( )A.alter table emp remove addcolumnB.alter table emp drop column addcolumnC.alter table emp delete column addcolumnD.alter table emp delete addcolumn
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);
下列哪个操作可以将表中的数据删除,并且不需要回滚删除后回收其所占有的空间,但表定义保留() A.DELETE FROM EMP;B.TUNCATE TABLE EMP;C.TUNCATE TABLE EMP REUSE STORAGE;D.DROP TABLE EMP;E.以上所述都不正确
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CHAR59 ( ),姓名CHAR60,部门CHAR59,家庭住址CHAR62,( );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(请作答此空)。A.ALTER TABLE Emp ADD工资CHAR(6，2)；B.UPDATA.11ABLE Emp ADD工资NUMERIC(6，2)；C.ALTER TABLE Emp ADD工资NUMERIC(6，2)；D.ALTER TABLE Emp MODIFY工资NUMERIC(6，2)；
删除emp表中所有数据，且无法rollback，以下语句哪个命令可以实现（）A、truncate table empB、drop table empC、delete * from empD、delete from emp
删除emp表的全部数据，但不提交，以下正确的语句是（）A、DELETE * FROM. EMPB、DELETE FROM EMPC、TRUNCATE TABLE EMPD、DELETE TABLE EMP"
DEPARTMENT 表包含以下列： DEPT_ID NUMBER, Primary Key DEPT_ABBR VARCHAR2(4) DEPT_NAME VARCHAR2(30) MGR_ID NUMBER EMPLOYEE 表包含以下列： EMPLOYEE_ID NUMBER EMP_LNAME VARCHAR2(25) EMP_FNAME VARCHAR2(25) DEPT_ID NUMBER JOB_ID NUMBER MGR_ID NUMBER SALARY NUMBER(9,2) HIRE_DATE DATE 请评估以下语句： ALTER TABLE employee ADD CONSTRAINT REFERENTIAL (mgr_id) TO department(mgr_id); 是以下哪个说法（）A、ALTER TABLE语句创建从EMPLOYEE表到DEPARTMENT表的引用约束条件B、ALTER TABLE语句创建从DEPARTMENT表到EMPLOYEE表的引用约束条件C、ADD CONSTRAINT子句存在语法错误，因此ALTER TABLE语句将会失败D、ALTER TABLE语句执行成功，但不重新创建引用约束条件
您需要从方案中的雇员表中删除EMP_FK_DEPT约束条件。应使用哪条语句（）A、DROP CONSTRAINT EMP_FK_DEPT FROM雇员B、DELETE CONSTRAINT EMP_FK_DEPT FROM雇员C、ALTER TABLE雇员DROP CONSTRAINT EMP_FK_DEPTD、ALTER TABLE雇员REMOVE CONSTRAINT EMP_FK_DEPT
如下能正确执行的语句是（）A、select * from table_name where 1=2B、truncate table table_nameC、delete from table_name where null=nullD、alter table table_name add column idd int
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 tableB、 Mapping TableC、 Clustered TableD、 Journal Table
有如下三步操作,并且均成功执行,请选择结果（） delete from emp; alter table emp add(addr varchar2(40)); rollback;A、emp表中数据处于回滚段中B、emp表中的数据被永久删除C、emp表中的数据没有变化D、原来的emp表中的数据被添加到新emp表中E、以上所述都不正确
下列哪个操作可以将表中的数据删除，并且不需要回滚删除后回收其所占有的空间，但表定义保留（）A、DELETE FROM EMP;B、TUNCATE TABLE EMP;C、TUNCATE TABLE EMP REUSE STORAGE;D、DROP TABLE EMP;E、以上所述都不正确
User SCOTT executes the following command on the EMP table but has not issued COMMIT， ROLLBACK，or any data definition language （DDL） command： SQL SELECT job FROM emp 2 WHERE job=’CLERK’ FOR UPDATE OF empno; SCOTT has opened another session to work with the database. Which three operations would wait when issued in SCOTT’s second session？（）A、LOCK TABLE emp IN SHARE MODE;B、LOCK TABLE emp IN EXCLUSIVE MODE;C、DELETE FROM emp WHERE job=’MANAGER’;D、INSERT INTO emp（empno，ename） VALUES （1289，’Dick’）;E、SELECT job FROM emp WHERE job=’CLERK’ FOR UPDATE OF empno;
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.
单选题下列哪个操作可以将表中的数据删除，并且不需要回滚删除后回收其所占有的空间，但表定义保留（）ADELETE FROM EMP;BTUNCATE TABLE EMP;CTUNCATE TABLE EMP REUSE STORAGE;DDROP TABLE EMP;E以上所述都不正确
单选题有如下三步操作,并且均成功执行,请选择结果（） delete from emp; alter table emp add(addr varchar2(40)); rollback;Aemp表中数据处于回滚段中Bemp表中的数据被永久删除Cemp表中的数据没有变化D原来的emp表中的数据被添加到新emp表中E以上所述都不正确
单选题Which SQL statement defines a FOREIGN KEY constraint on the DEPTNO column of the EMP table?（）ACREATE TABLE EMP (empno NUMBER(4), ename VARCHAR2(35), deptno NUMBER(7,2) NOT NULL, CONSTRAINT emp_deptno_fk FOREIGN KEY deptno REFERENCES dept deptno);BCREATE TABLE EMP (empno NUMBER(4), ename VARCHAR2(35), deptno NUMBER(7,2) CONSTRAINT emp_deptno_fk REFERENCES dept (deptno));CCREATE TABLE EMP (empno NUMBER(4), ename VARCHAR2(35), deptno NUMBER(7,2) NOT NULL, CONSTRAINT emp_deptno_fk REFERENCES dept (deptno) FOREIGN KEY (deptno));DCREATE TABLE EMP (empno NUMBER(4), ename VARCHAR2(35), deptno NUMBER(7,2) FOREIGN KEY CONSTRAINT emp_deptno_fk REFERENCES dept (deptno));
单选题The EMP table has these columns: ENAME VARCHAR2(35) SALARY NUMBER(8,2) HIRE_DATE DATE Management wants a list of names of employees who have been with the company for more than five years. Which SQL statement displays the required results? （）ASELECT ENAME FROM EMP WHERE SYSDATE-HIRE_DATE 5;BSELECT ENAME FROM EMP WHERE HIRE_DATE-SYSDATE 5;CSELECT ENAME FROM EMP WHERE (SYSDATE_HIRE_DATE)/365 5;DSELECT ENAME FROM EMP WHERE (SYSDATE_HIRE_DATE)*/365 5;
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 tableB Mapping TableC Clustered TableD Journal Table
单选题Examine the structure of the EMPLOYEES table: EMPLOYEE_ID NUMBER Primary Key FIRST_NAME VARCHAR2(25) LAST_NAME VARCHAR2(25) HIRE_DATE DATE You issue these statements: CREATE table new_emp ( employee_id NUMBER, name VARCHAR2(30)); INSERT INTO new_emp SELECT employee_id , last_name from employees; Savepoint s1; UPDATE new_emp set name = UPPER(name); Savepoint s2; Delete from new_emp; Rollback to s2; Delete from new_emp where employee_id =180; UPDATE new_emp set name = 'James'; Rollback to s2; UPDATE new_emp set name = 'James' WHERE employee_id =180; Rollback; At the end of this transaction, what is true?（）AYou have no rows in the table.BYou have an employee with the name of James.CYou cannot roll back to the same savepoint more than once.DYour last update fails to update any rows because employee ID 180 was already deleted.
单选题Examine the structure of the EMP_DEPT_VU view: Column Name Type Remarks EMPLOYEE_ID NUMBER From the EMPLOYEES table EMP_NAME VARCHAR2(30) From the EMPLOYEES table JOB_ID VARCHAR2(20) From the EMPLOYEES table SALARY NUMBER From the EMPLOYEES table DEPARTMENT_ID NUMBER From the DEPARTMENTS table DEPT_NAME VARCHAR2(30) From the DEPARTMENTS table Which SQL statement produces an error?（）ASELECT * FROM emp_dept_vu;BSELECT department_id, SUM(salary) FROM emp_dept_vu GROUP BY department _ id;CSELECT department_id, job_id, AVG(salary) FROM emp_dept_vu GROUP BY department _ id, job_id;DSELECT job_id, SUM(salary) FROM emp_dept_vu WHERE department_id IN (10,20) GROUP BY job_id HAVING SUM (salary) 20000ENone of the statements produce an error; all are valid.
多选题User SCOTT executes the following command on the EMP table but has not issued COMMIT， ROLLBACK，or any data definition language （DDL） command： SQL SELECT job FROM emp 2 WHERE job=’CLERK’ FOR UPDATE OF empno; SCOTT has opened another session to work with the database. Which three operations would wait when issued in SCOTT’s second session？（）ALOCK TABLE emp IN SHARE MODE;BLOCK TABLE emp IN EXCLUSIVE MODE;CDELETE FROM emp WHERE job=’MANAGER’;DINSERT INTO emp（empno，ename） VALUES （1289，’Dick’）;ESELECT job FROM emp WHERE job=’CLERK’ FOR UPDATE OF empno;
多选题User SCOTT executes the following command on the EMP table but has not issued COMMIT， ROLLBACK， or any data definition language （DDL） command： SQL SELECT ename FROM emp 2 WHERE job=’CLERK’ FOR UPDATE OF empno； SCOTT has opened another session to work with the database instance. Which three operations wouldwait when issued in SCOTT’s second session（）ALOCK TABLE emp IN SHARE MODE；BLOCK TABLE emp IN EXCLUSIVE MODE；CUPDATE emp SET sal=sal*1.2 WHERE job=MANAGER；DINSERT INTO emp（empno，ename） VALUES （1289，’Harry’）；ESELECT ename FROM emp WHERE job=’CLERK’ FOR UPDATE OF empno；
多选题User SCOTT executes the following command on the EMP table but has not issued COMMIT， ROLLBACK， orany data definition language （DDL） command： SQL SELECT ename FROM emp WHERE job=’CLERK’ FOR UPDATE OF empno； SCOTT has opened another session to work with the database instance. Which three operations would waitwhen issued in SCOTT’s second session（）ALOCK TABLE emp IN SHARE MODE；BLOCK TABLE emp IN EXCLUSIVE MODE；CUPDATE emp SET sal=sal*1.2 WHERE job=ANAGER？UPDATE emp SET sal=sal*1.2 WHERE job=？ANAGER？DINSERT INTO emp（empno，ename） VALUES （1289，’Harry’）；ESELECT ename FROM emp WHERE job=’CLERK’ FOR UPDATE OF empno
单选题Examine the structure of the EMPLOYEES table: EMPLOYEE_ID NUMBER Primary Key FIRST_NAME VARCHAR2(25) LAST_NAME VARCHAR2(25) HIRE_DATE DATE You issue these statements: CREATE table new_emp ( employe_id NUMBER, name VARCGAR2(30)); INSERT INTO new_emp SELECT employee_id, last_name from employees; Savepoint s1; UPDATE new_emp set name = UPPER(name); Savepoint s2; Delete from new_emp; Rollback to s2; Delete from new_emp where employee_id=180; UPDATE new_emp set name = 'James'; Rollback to s2; UPDATE new_emp sey name = 'James' Where employee_id=180; Rollback; At the end of this transaction, what is true?（）AYou have no rows in the table.BYou have an employee with the name of James.CYou cannot roll back to the same savepoint more than once.DYour last update fails to update any rows because employee ID 180 was already deleted.