单项选择题X 纠错
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.
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多项选择题
A.SUM(start_date)
B.AVG(start_date)
C.COUNT(start_date)
D.AVG(start_date, end_date)
E.MIN(start_date)
F.MAXIMUM(start_date)
单项选择题
A.The statement executes successfully and returns the student ID and sum of all marks for each student who obtained more than the average mark in each subject.
B.The statement returns an error at the SELECT clause.
C.The statement returns an error at the WHERE clause.
D.The statement returns an error at the ORDER BY clause.
多项选择题
A.SER_NO
B.ORDER_ID
C.STATUS
D.PROD_ID
E.ORD_TOTAL
F.composite index on ORDER_ID and ORDER_DATE
单项选择题
A.The SQL statement displays the desired results.
B.The column in the WHERE clause should be changed to display the desired results.
C.The operator in the WHERE clause should be changed to display the desired results.
D.The WHERE clause should be changed to use an outer join to display the desired results.
多项选择题
A.You want to create a nonequijoin.
B.The tables to be joined have multiple NULL columns.
C.The tables to be joined have columns of the same name and different data types.
D.The tables to be joined have columns with the same name and compatible data types.
E.You want to use a NATURAL join, but you want to restrict the number of columns in the join condition.
多项选择题
A.convert 10 to 'TEN'
B.convert '10' to 10
C.convert 10 to '10'
D.convert 'TEN' to 10
E.convert a date to a character expression
F.convert a character expression to a date
单项选择题
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 deleted.
多项选择题
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.
多项选择题
A.TIMESTAMP
B.INTERVAL MONTH TO DAY
C.INTERVAL DAY TO SECOND
D.INTERVAL YEAR TO MONTH
E.TIMESTAMP WITH DATABASE TIMEZONE
单项选择题
A.INSERT INTO employees VALUES (emp_id_seq.NEXTVAL, '&ename', '&jobid', 2000, NULL, &did);
B.INSERT INTO employees VALUES (emp_id_seq.NEXTVAL, '&ename', '&jobid', 2000, NULL, &did IN (20,50));
C.INSERT INTO (SELECT * FROM employees WHERE department_id IN (20,50)) VALUES (emp_id_seq.NEXTVAL, '&ename', '&jobid', 2000, NULL, &did);
D.INSERT INTO (SELECT * FROM employees WHERE department_id IN (20,50) WITH CHECK OPTION) VALUES (emp_id_seq.NEXTVAL, '&ename', '&jobid', 2000, NULL, &did);
E.INSERT INTO (SELECT * FROM employees WHERE (department_id = 20 AND department_id = 50) WITH CHECK OPTION ) VALUES (emp_id_seq.NEXTVAL, '&ename', '&jobid', 2000, NULL, &did);