单选题The EMPLOYEES table has these columns: LAST NAME VARCHAR2(35) SALARY NUMBER(8,2) HIRE_DATE DATE Management wants to add a default value to the SALARY column. You plan to alter the table by using this SQL statement: ALTER TABLE EMPLOYEES MODIFY ( SALARY DEFAULT 5000); What is true about your ALTER statement?（）AColumn definitions cannot be altered to add DEFAULT values.BA change to the DEFAULT value affects only subsequent insertions to the table.CColumn definitions cannot be altered at add DEFAULT values for columns with a NUMBER data type.DAll the rows that have a NULL value for the SALARY column will be updated with the value 5000.
单选题
The EMPLOYEES table has these columns: LAST NAME VARCHAR2(35) SALARY NUMBER(8,2) HIRE_DATE DATE Management wants to add a default value to the SALARY column. You plan to alter the table by using this SQL statement: ALTER TABLE EMPLOYEES MODIFY ( SALARY DEFAULT 5000); What is true about your ALTER statement?（）
A
Column definitions cannot be altered to add DEFAULT values.
B
A change to the DEFAULT value affects only subsequent insertions to the table.
C
Column definitions cannot be altered at add DEFAULT values for columns with a NUMBER data type.
D
All the rows that have a NULL value for the SALARY column will be updated with the value 5000.
参考解析
解析：
暂无解析
相关考题：
The EMPLOYEES table contains these columns:LAST_NAME VARCHAR2 (25)SALARY NUMBER (6,2)COMMISSION_PCT NUMBER (6)You need to write a query that will produce these results:1. Display the salary multiplied by the commission_pct.2. Exclude employees with a zero commission_pct.3. Display a zero for employees with a null commission value. Evaluate the SQL statement:SELECT LAST_NAME, SALARY*COMMISSION_PCT FROM EMPLOYEESWHERE COMMISSION_PCT IS NOT NULL;What does the statement provide? （）A. All of the desired resultsB. Two of the desired resultsC. One of the desired resultsD. An error statement
The EMP table has these columns:ENAME VARCHAR2(35)SALARY NUMBER(8,2)HIRE_DATE DATEManagement 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? （）A. SELECT ENAME FROM EMP WHERE SYSDATE-HIRE_DATE 5;B. SELECT ENAME FROM EMP WHERE HIRE_DATE-SYSDATE 5;C. SELECT ENAME FROM EMP WHERE (SYSDATE_HIRE_DATE)/365 5;D. SELECT ENAME FROM EMP WHERE (SYSDATE_HIRE_DATE)*/365 5;
The EMPLOYEE tables has these columns:LAST_NAME VARCHAR2(35)SALARY NUMBER(8,2)COMMISSION_PCT NUMBER(5,2)You want to display the name and annual salary multiplied by the commission_pct for all employees. For records that have a NULL commission_pct, a zero must be displayed against the calculated column.Which SQL statement displays the desired results? （）A. SELECT last_name, (salary * 12) * commission_pct FROM EMPLOYEES;B. SELECT last_name, (salary * 12) * IFNULL(commission_pct, 0) FROM EMPLOYEES;C. SELECT last_name, (salary * 12) * NVL2(commission_pct, 0) FROM EMPLOYEES;D. SELECT last_name, (salary * 12) * NVL(commission_pct, 0) FROM EMPLOYEES;
The EMPLOYEES table has these columns:Management wants to add a default value to the SALARY column. You plan to alter the table by using this SQL statement:What is true about your ALTER statement?() A. Column definitions cannot be altered to add DEFAULT values.B. A change to the DEFAULT value affects only subsequent insertions to the table.C. Column definitions cannot be altered at add DEFAULT values for columns with a NUMBER data type.D. All the rows that have a NULL value for the SALARY column will be updated with the value 5000.
您在公司的数据库中成功创建了名为SALARY的表。您现在要通过向引用EMPLOYEES表的匹配列的SALARY表添加FOREIGNKEY约束条件来建立EMPLOYEES表与SALARY表之间的父/子关系。尚未向SALARY表添加任何数据。应执行以下哪条语句（）A、ALTER TABLE salary ADD CONSTRAINT fk_employee_id_01 FOREIGN KEY（employee_id）REFERENCES employees（employee_id）B、ALTER TABLE salary ADD CONSTRAINT fk_employee_id_ FOREIGN KEY BETWEEN salary（employee_id）AND employees（employee_id）C、ALTER TABLE salary FOREIGN KEY CONSTRAINT fk_employee_id_REFERENCES employees（employee_id）D、ALTER TABLE salary ADD CONSTRAINT fk_employee_id_FOREIGN KEY salary（employee_id）=employees（employee_id）
The EMPLOYEES table has these columns: LAST NAME VARCHAR2(35) SALARY NUMBER(8,2) HIRE_DATE DATE Management wants to add a default value to the SALARY column. You plan to alter the table by using this SQL statement: ALTER TABLE EMPLOYEES MODIFY ( SALARY DEFAULT 5000); What is true about your ALTER statement?（）A、Column definitions cannot be altered to add DEFAULT values.B、A change to the DEFAULT value affects only subsequent insertions to the table.C、Column definitions cannot be altered at add DEFAULT values for columns with a NUMBER data type.D、All the rows that have a NULL value for the SALARY column will be updated with the value 5000.
The EMPLOYEE tables has these columns: LAST_NAME VARCHAR2(35) SALARY NUMBER(8,2) COMMISSION_PCT NUMBER(5,2) You want to display the name and annual salary multiplied by the commission_pct for all employees. For records that have a NULL commission_pct, a zero must be displayed against the calculated column. Which SQL statement displays the desired results?（）A、SELECT last_name, (salary * 12) * commission_pct FROM EMPLOYEES;B、SELECT last_name, (salary * 12) * IFNULL(commission_pct, 0) FROM EMPLOYEES;C、SELECT last_name, (salary * 12) * NVL2(commission_pct, 0) FROM EMPLOYEES;D、SELECT last_name, (salary * 12) * NVL(commission_pct, 0) FROM EMPLOYEES;
You own a table called EMPLOYEES with this table structure: EMPLOYEE_ID NUMBER Primary Key FIRST_NAME VARCHAR2(25) LAST_NAME VARCHAR2(25) HIRE_DATE DATE What happens when you execute this DELETE statement? DELETE employees;（）A、You get an error because of a primary key violation.B、The data and structure of the EMPLOYEES table are deleted.C、The data in the EMPLOYEES table is deleted but not the structure.D、You get an error because the statement is not syntactically correct.
Management has asked you to calculate the value 12*salary* commission_pct for all the employees in the EMP table. The EMP table contains these columns: LAST NAME VARCNAR2(35) NOT NULL SALARY NUMBER(9,2) NOT NULL COMMISION_PCT NUMBER(4,2) Which statement ensures that a value is displayed in the calculated columns for all employees?（）A、SELECT last_name, 12*salary* commission_pct FROM emp;B、SELECT last_name, 12*salary* (commission_pct,0) FROM emp;C、SELECT last_name, 12*salary*(nvl(commission_pct,0)) FROM emp;D、SELECT last_name, 12*salary*(decode(commission_pct,0)) FROM emp;
The EMPLOYEES table contains these columns: LAST_NAME VARCHAR2 (25) SALARY NUMBER (6,2) COMMISSION_PCT NUMBER (6) You need to write a query that will produce these results: 1. Display the salary multiplied by the commission_pct. 2. Exclude employees with a zero commission_pct. 3. Display a zero for employees with a null commission value. Evaluate the SQL statement: SELECT LAST_NAME, SALARY*COMMISSION_PCT FROM EMPLOYEES WHERE COMMISSION_PCT IS NOT NULL; What does the statement provide? （）A、All of the desired resultsB、Two of the desired resultsC、One of the desired resultsD、An error statement
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? （）A、SELECT ENAME FROM EMP WHERE SYSDATE-HIRE_DATE 5;B、SELECT ENAME FROM EMP WHERE HIRE_DATE-SYSDATE 5;C、SELECT ENAME FROM EMP WHERE (SYSDATE_HIRE_DATE)/365 5;D、SELECT ENAME FROM EMP WHERE (SYSDATE_HIRE_DATE)*/365 5;
The EMPLOYEES table has these columns:LAST_NAME VARCHAR2(35) SALARY NUMBER(8,2) HIRE_DATE DATEManagement wants to add a default value to the SALARY column. You plan to alter the table by using this SQL statement:ALTER TABLE EMPLOYEES MODIFY (SALARY DEFAULT 5000);Which is true about your ALTER statement?（）A、Column definitions cannot be altered to add DEFAULT values.B、A change to the DEFAULT value affects only subsequent insertions to the table.C、Column definitions cannot be altered to add DEFAULT values for columns with a NUMBER data type.D、All the rows that have a NULL value for the SALARY column will be updated with the value 5000.
单选题The EMP table contains these columns: EMPLOYEE_ID NUMBER(4) EMPNAME VARCHAR2 (25) SALARY NUMBER(9,2) HIRE_DATE DATE You query the database with this SQL statement: SELECT empname,hire_date HIREDATE, salary FROM EMP ORDER BY hire_date; How will the results be sorted?（）ArandomlyBascending by dateCdescending by dateDascending alphabeticallyEdescending alphabetically
单选题You own a table called EMPLOYEES with this table structure: EMPLOYEE_ID NUMBER Primary Key FIRST_NAME VARCHAR2(25) LAST_NAME VARCHAR2(25) HIRE_DATE DATE What happens when you execute this DELETE statement? DELETE employees; （）AYou get an error because of a primary key violation.BThe data and structure of the EMPLOYEES table are deleted.CThe data in the EMPLOYEES table is deleted but not the structure.DYou get an error because the statement is not syntactically correct.
单选题Management has asked you to calculate the value 12*salary* commission_pct for all the employees in the EMP table. The EMP table contains these columns: LAST NAME VARCNAR2(35) NOT NULL SALARY NUMBER(9,2) NOT NULL COMMISION_PCT NUMBER(4,2) Which statement ensures that a value is displayed in the calculated columns for all employees?（）ASELECT last_name, 12*salary* commission_pct FROM emp;BSELECT last_name, 12*salary* (commission_pct,0) FROM emp;CSELECT last_name, 12*salary*(nvl(commission_pct,0)) FROM emp;DSELECT last_name, 12*salary*(decode(commission_pct,0)) FROM emp;
单选题The EMPLOYEE tables has these columns: LAST_NAME VARCHAR2(35) SALARY NUMBER(8,2) COMMISSION_PCT NUMBER(5,2) You want to display the name and annual salary multiplied by the commission_pct for all employees. For records that have a NULL commission_pct, a zero must be displayed against the calculated column. Which SQL statement displays the desired results?（）ASELECT last_name, (salary * 12) * commission_pct FROM EMPLOYEES;BSELECT last_name, (salary * 12) * IFNULL(commission_pct, 0) FROM EMPLOYEES;CSELECT last_name, (salary * 12) * NVL2(commission_pct, 0) FROM EMPLOYEES;DSELECT last_name, (salary * 12) * NVL(commission_pct, 0) FROM EMPLOYEES;
单选题Examine the description of the EMPLOYEES table: EMP_ID NUMBER(4) NOT NULL LAST_ NAME VARCHAR2(30) NOT NULL FIRST_NAME VARCHAR2(30) DEPT_ID NUMBER(2) JOB_CAT VARCHAR2(30) SALARY NUMBER(8,2) Which statement shows the department ID, minimum salary, and maximum salary paid in that department, only if the minimum salary is less than 5000 and maximum salary is more than 15000?（）ASELECT dept_id, MIN(salary), MAX(salary) FROM employees WHERE MIN(salary) 5000 AND MAX(salary) 15000;BSELECT dept_id, MIN(salary), MAX(salary) FROM employees WHERE MIN(salary) 5000 AND MAX(salary) 15000 GROUP BY dept_id;CSELECT dept_id, MIN(salary), MAX(salary) FROM employees HAVING MIN(salary) 5000 AND MAX(salary) 15000;DSELECT dept_id, MIN(salary), MAX(salary) FROM employees GROUP BY dept_id HAVING MIN(salary) 5000 AND MAX(salary) 15000;ESELECT dept_id, MIN(salary), MAX(salary) FROM employees GROUP BY dept_id, salary HAVING MIN(salary) 5000 AND MAX(salary) 15000;
单选题Evaluate these two SQL statements: SELECT last_name, salary , hire_date FROM EMPLOYEES ORDER BY salary DESC; SELECT last_name, salary , hire_date FROM EMPLOYEES ORDER BY 2 DESC; What is true about them?（）AThe two statements produce identical results.BThe second statement returns a syntax error.CThere is no need to specify DESC because the results are sorted in descending order by default.DThe two statements can be made to produce identical results by adding a column alias for the salary column in the second SQL statement.
单选题You own a table called EMPLOYEES with this table structure: EMPLOYEE_ID NUMBER Primary Key FIRST_NAME VARCHAR2(25) LAST_NAME VARCHAR2(25) HIRE_DATE DATE What happens when you execute this DELETE statement? DELETE employees;（）AYou get an error because of a primary key violation.BThe data and structure of the EMPLOYEES table are deleted.CThe data in the EMPLOYEES table is deleted but not the structure.DYou get an error because the statement is not syntactically correct.
单选题Examine the description of the EMPLOYEES table: EMP_ID NUMBER(4) NOT NULL LAST_NAME VARCHAR2(30) NOT NULL FIRST_NAME VARCHAR2(30) DEPT_ID NUMBER(2) JOB_CAT VARCHAR2(30) SALARY NUMBER(8,2) Which statement shows the department ID, minimum salary, and maximum salary paid in that department, only of the minimum salary is less then 5000 and the maximum salary is more than 15000?（）ASELECT dept_id, MIN(salary(, MAX(salary) FROM employees WHERE MIN(salary) 5000 AND MAX (salary) 15000;BSELECT dept_id, MIN(salary), MAX(salary) FROM employees WHERE MIN(salary) 5000 AND MAX(salary) 15000 GROUP BY dept_id;CSELECT dept_id, MIN(salary), MAX(salary) FROM employees HAVING MIN(salary) 5000 AND MAX (salary) 15000;DSELECT dept_id, MIN(salary), MAX(salary) FROM employees GROUP BY dept_id HAVING MIN (salary) 5000 AND MAX(salary)ESELECT dept_id, MIN(salary), MAX(salary) FROM employees GROUP BY dept_id, salary HAVING MIN (salary) 5000 AND MAX (salary) 15000;
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The EMP table contains these columns: EMPLOYEE_ID NUMBER(4) EMPNAME VARCHAR2 (25) SALARY NUMBER(9,2) HIRE_DATE DATE You query the database with this SQL statement: SELECT empname,hire_date HIREDATE, salary FROM EMP ORDER BY hire_date; How will the results be sorted?（）ArandomlyBascending by dateCdescending by dateDascending alphabeticallyEdescending alphabetically
单选题The EMPLOYEES table contains these columns: LAST_NAME VARCHAR2 (25) SALARY NUMBER (6,2) COMMISSION_PCT NUMBER (6) You need to write a query that will produce these results: 1. Display the salary multiplied by the commission_pct. 2. Exclude employees with a zero commission_pct. 3. Display a zero for employees with a null commission value. Evaluate the SQL statement: SELECT LAST_NAME, SALARY*COMMISSION_PCT FROM EMPLOYEES WHERE COMMISSION_PCT IS NOT NULL; What does the statement provide?（）AAll of the desired resultsBTwo of the desired resultsCOne of the desired resultsDAn error statement
单选题The EMPLOYEES table has these columns:LAST_NAME VARCHAR2(35) SALARY NUMBER(8,2) HIRE_DATE DATEManagement wants to add a default value to the SALARY column. You plan to alter the table by using this SQL statement:ALTER TABLE EMPLOYEES MODIFY (SALARY DEFAULT 5000);Which is true about your ALTER statement?（）AColumn definitions cannot be altered to add DEFAULT values.BA change to the DEFAULT value affects only subsequent insertions to the table.CColumn definitions cannot be altered to add DEFAULT values for columns with a NUMBER data type.DAll the rows that have a NULL value for the SALARY column will be updated with the value 5000.
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The EMPLOYEES table contains these columns: LAST_NAME VARCHAR2 (25) SALARY NUMBER (6,2) COMMISSION_PCT NUMBER (6) You need to write a query that will produce these results: 1. Display the salary multiplied by the commission_pct. 2. Exclude employees with a zero commission_pct. 3. Display a zero for employees with a null commission value. Evaluate the SQL statement: SELECT LAST_NAME, SALARY*COMMISSION_PCT FROM EMPLOYEES WHERE COMMISSION_PCT IS NOT NULL; What does the statement provide? （）AAll of the desired resultsBTwo of the desired resultsCOne of the desired resultsDAn error statement
单选题Management has asked you to calculate the value 12*salary* commission_pct for all the employees in the EMP table. The EMP table contains these columns: LAST NAME VARCNAR2(35) NOT NULL SALARY NUMBER(9,2) NOT NULL COMMISION_PCT NUMBER(4,2) Which statement ensures that a value is displayed in the calculated columns for all employees? （）ASELECT last_name, 12*salary* commission_pct FROM emp;BSELECT last_name, 12*salary* (commission_pct,0) FROM emp;CSELECT last_name, 12*salary*(nvl(commission_pct,0)) FROM emp;DSELECT last_name, 12*salary*(decode(commission_pct,0)) FROM emp;