单项选择题
Which are iSQL*Plus commands? （）
A.INSERT
B.UPDATE
C.SELECT
D.DESCRIBE
E.DELETE
F.RENAME
相关考题
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多项选择题
Examine the description of the MARKS table: STD_ID NUMBER(4) STUDENT_NAME VARCHAR2(30) SUBJ1 NUMBER(3) SUBJ2 NUMBER(3) SUBJ3 NUMBER(3) SUBJ1, SUBJ2, and SUBJ3 indicate the marks (grades) obtained by a student in the three subjects. Which two statements are valid? （）
A.SELECT SUM(subj1, subj2, subj3) FROM marks;
B.SELECT SUM(subj1 + subj2 + subj3) FROM marks;
C.SELECT SUM(subj1), SUM(subj2), SUM(subj3) FROM marks;
D.SELECT MAX(subj1, subj2, subj3) FROM marks;
E.SELECT MINIMUM(subj1) FROM marks;
F.SELECT COUNT(std_id) FROM marks WHERE subj1 >= AVG(subj1); -
单项选择题
Examine the description of the EMPLOYEES table: Which statement produces the number of different departments that have employees with last name Smith?（）
A.SELECT COUNT(*) FROM employees WHERE last_name='Smith';
B.SELECT COUNT(dept_id) FROM employees WHERE last_name='Smith';
C.SELECT DISTINCT(COUNT(dept_id)) FROM employees WHERE last_name='Smith';
D.SELECT COUNT(DISTINCT dept_id) FROM employees WHERE last_name='Smith';
E.SELECT UNIQUE(dept_id) FROM employees WHERE last_name='Smith'; -
单项选择题
Which SELECT statement should you use to extract the year from the system date and display it in the format "1998"?（）
A.SELECT TO_CHAR(SYSDATE,'yyyy') FROM dual;
B.SELECT TO_DATE(SYSDATE,'yyyy') FROM dual;
C.SELECT DECODE(SUBSTR(SYSDATE, 8), 'YYYY') FROM dual;
D.SELECT DECODE(SUBSTR(SYSDATE, 8), 'year') FROM dual;
E.SELECT TO_CHAR(SUBSTR(SYSDATE, 8,2),'yyyy') FROM dual;
