多项选择题
Examine the structure of the EMPLOYEES table:
EMPLOYEE_ID NUMBER NOT NULL, Primary Key
EMP_NAME VARCHAR2(30)
JOB_ID NUMBER\
SAL NUMBER
MGR_ID NUMBER References EMPLOYEE_ID column
DEPARTMENT_ID NUMBER Foreign key to DEPARTMENT_ID column of the DEPARTMENTS table You created a sequence called EMP_ID_SEQ in
orderto populate sequential values for the EMPLOYEE_ID column of the EMPLOYEES table. Which two statements regarding the EMP_ID_SEQ sequence are true? ()
A. You cannot use the EMP_ID_SEQ sequence to populate the JOB_ID column.
B. The EMP_ID_SEQ sequence is invalidated when you modify the EMPLOYEE_ID column.
C. The EMP_ID_SEQ sequence is not affected by modifications to the EMPLOYEES table.
D. Any other column of NUMBER data type in your schema can use the EMP_ID_SEQ sequence.
E. The EMP_ID_SEQ sequence is dropped automatically when you drop the EMPLOYEES table.
F. The EMP_ID_SEQ sequence is dropped automatically when you drop the EMPLOYEE_ID column.
相关考题
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多项选择题
Which four are types of functions available in SQL? ()
A. string
B. character
C. integer
D. calendar
E. numeric
F. translation
G. date
H. conversion -
单项选择题
A SELECT statement can be used to perform these three functions: 1. Choose rows from a table. 2. Choose columns from a table 3. Bring together data that is stored in different tables by creating a link between them. Which set of keywords describes these capabilities? ()
A. difference, projection, join
B. selection, projection, join
C. selection, intersection, join
D. intersection, projection, join
E. difference, projection, product -
单项选择题
Which is a valid CREATE TABLE statement? ()
A. CREATE TABLE EMP9$# AS (empid number(2));
B. CREATE TABLE EMP*123 AS (empid number(2));
C. CREATE TABLE PACKAGE AS (packid number(2));
D. CREATE TABLE 1EMP_TEST AS (empid number(2));
