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1题：
A. You cannot roll back this statement.
B. All pending transactions are committed.
C. All views based on the DEPT table are deleted.
D. All indexes based on the DEPT table are dropped.
E. All data in the table is deleted, and the table structure is also deleted.
F. All data in the table is deleted, but the structure of the table is retained.
G. All synonyms based on the DEPT table are deleted.
第2题：
Examine the structure of the EMPLOYEES table:You need to update the records of employees 103 and 115. The UPDATE statement you specify should update the rows with the values specified below:Which UPDATE statement meets the requirements?（）
A.
B.
C.
D.
E.
第3题：
A. An error is generated.
B. You will have two identical tables in the HR schema with different names.
C. You create a table called employees in the HR schema based on you EMP table.
D. You create an alternative name for the employees table in the HR schema in your own schema.
第4题：
Examine the data in the EMPLOYEES table.On the EMPLOYEES table, EMPLOYEE_ID is the primary key. MGR_ID is the ID of managers and refers to the EMPLOYEE_ID. The JOB_ID column is a NOT NULL column.Evaluate this DELETE statement:Why does the DELETE statement fail when you execute it?（）
A. There is no row with dept_id 90 in the EMPLOYEES table.
B. You cannot delete the JOB_ID column because it is a NOT NULL column.
C. You cannot specify column names in the DELETE clause of the DELETE statement.
D. You cannot delete the EMPLOYEE_ID column because it is the primary key of the table.
第5题：
A. You have no rows in the table.
B. You have an employee with the name of James.
C. You cannot roll back to the same savepoint more than once.
D. Your last update fails to update any rows because employee ID 180 was already eleted.
第6题：
You added a PHONE_NUMBER column of NUMBER data type to an existing EMPLOYEES table. The EMPLOYEES table already contains records of 100 employees. Now, you want to enter the phone numbers of each of the 100 employees into the table. Some of the employees may not have a phone number available. Which data manipulation operation do you perform? （）
A. MERGE
B. INSERT
C. UPDATE
D. ADD
E. ENTER
F. You cannot enter the phone numbers for the existing employee records.
第7题：
A.
B.
C.
D.
第8题：
You own a table called EMPLOYEES with this table structure: EMPLOYEE_ID NUMBER Primary KeyFIRST_NAME VARCHAR2(25)LAST_NAME VARCHAR2(25)HIRE_DATE DATEWhat 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.
第9题：
Examine the data from the EMP table:The COMMISSION column shows the monthly commission earned by the employee.Which three tasks would require subqueries or joins in order to perform in a single step?（）
A. Deleting the records of employees who do not earn commission.
B. Increasing the commission of employee 3 by the average commission earned in department 20.
C. Finding the number of employees who do NOT earn commission and are working for department 20.
D. Inserting into the table a new employee 10 who works for department 20 and earns a commission that is equal to the commission earned by employee 3.
E. Creating a table called COMMISSION that has the same structure and data as the columns EMP_ID and COMMISSIONS of the EMP table.
F. Decreasing the commission by 150 for the employees who are working in department 30 and earning a commission of more then 800.
第10题：
Examine the data in the EMPLOYEES and DEPARTMENTS tables:Also examine the SQL statements that create the EMPLOYEES and DEPARTMENTS tables:On the EMPLOYEES table, EMPLOYEE_ID is the primary key.MGR_ID is the ID of managers and refers to the EMPLOYEE_ID.DEPT_ID is foreign key to DEPARTMENT_ID column of the DEPARTMENTS table.On the DEPARTMENTS table, DEPARTMENT_ID is the primary key.Examine this DELETE statement:What happens when you execute the DELETE statement?（）
A. Only the row with department ID 40 is deleted in the DEPARTMENTS table.
B. The statement fails because there are child records in the EMPLOYEES table with department ID 40.
C. The row with department ID 40 is deleted in the DEPARTMENTS table. Also the rows with employee IDs 110 and 106 are deleted from the EMPLOYEES table.
D. The row with department ID 40 is deleted in the DEPARTMENTS table. Also the rows with employee IDs 106 and 110 and the employees working under employee 110 are deleted from the EMPLOYEES table.
E. The row with department ID 40 is deleted in the DEPARTMENTS table. Also all the rows in the EMPLOYEES table are deleted.
F. The statement fails because there are no columns specifies in the DELETE clause of the DELETE statement.