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? （）A SELECT E

第1题：

第2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.

第3题：

第4题：

The PRODUCTS table has these columns: PRODUCT_ID NUMBER(4) PRODUCT_NAME VARCHAR2(45) PRICE NUMBER(8,2) Evaluate this SQL statement: SELECT * FROM PRODUCTS ORDER BY price, product _ name; What is true about the SQL statement?（）

• A、The results are not sorted.
• B、The results are sorted numerically.
• C、The results are sorted alphabetically.
• D、The results are sorted numerically and then alphabetically.

第5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?（）

• 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;

第6题：

第7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?（）

• 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;

第8题：

第9题：

You need to display the last names of those employees who have the letter "A" as the second character in their names. Which SQL statement displays the required results? （）

• A、SELECT last_name FROM EMP WHERE last_ name LIKE '_A%';
• B、SELECT last_name FROM EMP WHERE last name ='*A%'
• C、SELECT last_name FROM EMP WHERE last name ='_A%';
• D、SELECT last_name FROM EMP WHERE last name LIKE '*A%'

第10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? （）

• 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;