1Z0-007單項(xiàng)選擇題每日一練(2020.05.18)

Examine the structure of the EMPLOYEES table:
Column name Data type Remarks
EMPLOYEE_ID NUMBER NOT NULL, Primary Key
LAST_NAME VARCNAR2(30)
FIRST_NAME VARCNAR2(30)
JOB_ID NUMBER
SAL NUMBER
MGR_ID NUMBER References EMPLOYEE_ID column
DEPARTMENT_ID NUMBER
You need to create an index called NAME_IDX on the first name and last name fields of the EMPLOYEES table. Which SQL statement would you use to perform this task?（）

Examine the structure of the EMPLOYEES table:
EMPLOYEE_ID NUMBER Primary Key
FIRST_NAME VARCHAR2 (25)
LAST_NAME VARCHAR2 (25)
HIRE_DATE DATE
Which UPDATE statement is valid?（）

Examine the structure of the EMPLOYEES and NEW_EMPLOYEES tables:
EMPLOYEES
EMPLOYEE_ID NUMBER Primary Key
FIRST_NAME VARCHAR2 (25)
LAST_NAME VARCHAR2 (25)
HIRE_DATE DATE
NEW EMPLOYEES
EMPLOYEE_ID NUMBER Primary Key
NAME VARCHAR2 (60)
Which DELETE statement is valid?（）