单项选择题
Which SQL statement defines a FOREIGN KEY constraint on the DEPTNO column of the EMP table?（）
A.CREATE TABLE EMP (empno NUMBER(4), ename VARCHAR2(35), deptno NUMBER(7,2) NOT NULL, CONSTRAINT emp_deptno_fk FOREIGN KEY deptno REFERENCES dept deptno);
B.CREATE TABLE EMP (empno NUMBER(4), ename VARCHAR2(35), deptno NUMBER(7,2) CONSTRAINT emp_deptno_fk REFERENCES dept (deptno));
C.CREATE TABLE EMP (empno NUMBER(4), ename VARCHAR2(35), deptno NUMBER(7,2) NOT NULL, CONSTRAINT emp_deptno_fk REFERENCES dept (deptno) FOREIGN KEY (deptno));
D.CREATE TABLE EMP (empno NUMBER(4), ename VARCHAR2(35), deptno NUMBER(7,2) FOREIGN KEY CONSTRAINT emp_deptno_fk REFERENCES dept (deptno));
相关考题
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单项选择题
Click the Exhibit button and examine the data in the EMPLOYEES and DEPARTMENTS tables.You want to retrieve all employees, whether or not they have matching departments in the departments table. Which query would you use?（）
A.SELECT last_name, department_name FROM employees NATURAL JOIN departments;
B.SELECT last_name, department_name FROM employees JOIN departments ;
C.SELECT last_name, department_name FROM employees e JOIN departments d ON (e.department_id = d.department_id);
D.SELECT last_name, department_name FROM employees e RIGHT OUTER JOIN departments d ON (e.department_id = d.department_id);
E.SELECT last_name, department_name FROM employees FULL JOIN departments ON (e.department_id = d.department_id);
F.SELECT last_name, department_name FROM employees e LEFT OUTER JOIN departments d ON (e.department_id = d.department_id); -
单项选择题
Which SQL statement generates the alias Annual Salary for the calculated column SALARY*12?（）
A.SELECT ename, salary*12 'Annual Salary' FROM employees;
B.SELECT ename, salary*12 "Annual Salary" FROM employees;
C.SELECT ename, salary*12 AS Annual Salary FROM employees;
D.SELECT ename, salary*12 AS INITCAP("ANNUAL SALARY") FROM employees -
单项选择题
What is true of using group functions on columns that contain NULL values?（）
A.Group functions on columns ignore NULL values.
B.Group functions on columns returning dates include NULL values.
C.Group functions on columns returning numbers include NULL values.
D.Group functions on columns cannot be accurately used on columns that contain NULL values.
E.Group functions on columns include NULL values in calculations if you use the keyword INC_NULLS.
