Column definitions cannot be altered to add DEFAULT values.
A change to the DEFAULT value affects only subsequent insertions to the table.
Column definitions cannot be altered to add DEFAULT values for columns with a NUMBER data type.
All the rows that have a NULL value for the SALARY column will be updated with the value 5000.
第1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) Which statement produces the number of different departments that have employees with last name Smith?（）
第2题：
all of the desired results
two of the desired results
one of the desired results
an error statement
第3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 results
B. Two of the desired results
C. One of the desired results
D. An error statement
第4题：
UPDATE employees SET first_name = 'John' SET last_name ='Smith' WHERE employee_id = 180;
UPDATE employees SET first_name = 'John', SET last_name ='Smith' WHERE employee_id = 180;
UPDATE employees SET first_name = 'John' AND last_name ='Smith' WHERE employee_id = 180;
UPDATE employees SET first_name = 'John', last_name ='Smith' WHERE employee_id = 180;
第5题：
UPDATE employees SET first_name = 'John' SET last_name = 'Smith' WHERE employee_id = 180;
UPDATE employees SET first_name = 'John', SET last_name = 'Smoth' WHERE employee_id = 180;
UPDATE employee SET first_name = 'John' AND last_name = 'Smith' WHERE employee_id = 180;
UPDATE employee SET first_name = 'John', last_name = 'Smith' WHERE employee_id = 180;
第6题：
You get an error because of a primary key violation.
The data and structure of the EMPLOYEES table are deleted.
The data in the EMPLOYEES table is deleted but not the structure.
You get an error because the statement is not syntactically correct.
第7题：
You get an error because of a primary key violation.
The data and structure of the EMPLOYEES table are deleted.
The data in the EMPLOYEES table is deleted but not the structure.
You get an error because the statement is not syntactically correct.
第8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9题：
Column definitions cannot be altered to add DEFAULT values.
A change to the DEFAULT value affects only subsequent insertions to the table.
Column definitions cannot be altered to add DEFAULT values for columns with a NUMBER data type.
All the rows that have a NULL value for the SALARY column will be updated with the value 5000.
第10题：
SELECT employee_id, last_name, job_id FROM employees WHERE job_id LIKE '%SA/_%' ESCAPE '/';
SELECT employee_id, last_name, job_id FROM employees WHERE job_id LIKE '%SA_';
SELECT employee_id, last_name, job_id FROM employees WHERE job_id LIKE '%SA_' ESCAPE /;
SELECT employee_id, last_name, job_id FROM employees WHERE job_id = '%SA_';