多項(xiàng)選擇題

Which four are valid Oracle constraint types? （）

A. CASCADE
B. UNIQUE
C. NONUNIQUE
D. CHECK
E. PRIMARY KEY
F. CONSTANT
G. NOT NULL

你可能感興趣的試題

The EMPLOYEES table contains these columns:
EMPLOYEE_ID NUMBER(4)
ENAME VARCHAR2 (25)
JOB_ID VARCHAR2(10)
Which SQL statement will return the ENAME, length of the ENAME, and the numeric position of the
letter "a" in the ENAME column, for those employees whose ENAME ends with a the letter "n"?（）

A. SELECT ENAME, LENGTH(ENAME), INSTR(ENAME, 'a') FROM EMPLOYEES WHERE SUBSTR (ENAME, -1,1) = 'n';
B. SELECT ENAME, LENGTH(ENAME), INSTR(ENAME, ,-1,1) FROM EMPLOYEES WHERE SUBSTR (ENAME, -1,1) = 'n';
C. SELECT ENAME, LENGTH(ENAME), SUBSTR(ENAME, -1,1) FROM EMPLOYEES WHERE INSTR (ENAME, 1,1) = 'n';
D. SELECT ENAME, LENGTH(ENAME), SUBSTR(ENAME, -1,1) FROM EMPLOYEES WHERE INSTR (ENAME, -1,1) = 'n';

單項(xiàng)選擇題

You own a table called EMPLOYEES with this table structure: EMPLOYEE_ID NUMBER Primary Key
FIRST_NAME VARCHAR2(25)
LAST_NAME VARCHAR2(25)
HIRE_DATE DATE
What 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.

Which four are valid Oracle constraint types? （）

你可能感興趣的試題

The EMPLOYEES table contains these columns: EMPLOYEE_ID NUMBER(4) ENAME VARCHAR2 (25) JOB_ID VARCHAR2(10) Which SQL statement will return the ENAME, length of the ENAME, and the numeric position of the letter "a" in the ENAME column, for those employees whose ENAME ends with a the letter "n"?（）

You own a table called EMPLOYEES with this table structure: EMPLOYEE_ID NUMBER Primary Key FIRST_NAME VARCHAR2(25) LAST_NAME VARCHAR2(25) HIRE_DATE DATE What happens when you execute this DELETE statement? DELETE employees; （）

The EMPLOYEES table contains these columns:
EMPLOYEE_ID NUMBER(4)
ENAME VARCHAR2 (25)
JOB_ID VARCHAR2(10)
Which SQL statement will return the ENAME, length of the ENAME, and the numeric position of the
letter "a" in the ENAME column, for those employees whose ENAME ends with a the letter "n"?（）

You own a table called EMPLOYEES with this table structure: EMPLOYEE_ID NUMBER Primary Key
FIRST_NAME VARCHAR2(25)
LAST_NAME VARCHAR2(25)
HIRE_DATE DATE
What happens when you execute this DELETE statement? DELETE employees; （）