单项选择题X 纠错
A.The indexed column is declared as NOT NULL.
B.The indexed columns are used in the FROM clause.
C.The indexed columns are part of an expression.
D.The indexed column contains a wide range of values.
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单项选择题
A.The inner query always sorts the results of the outer query.
B.The outer query always sorts the results of the inner query.
C.The outer query must return a value to the inner query.
D.The inner query returns a value to the outer query.
E.The inner query must always return a value or the outer query will give an error.
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.SELECT * FROM employees where salary > (SELECT MIN(salary) FROM employees GROUP BY department_id);
B.SELECT * FROM employees WHERE salary = (SELECT AVG(salary) FROM employees GROUP BY department_id);
C.SELECT distinct department_id FROM employees WHERE salary > ANY (SELECT AVG(salary) FROM employees GROUP BY department_id);
D.SELECT department_id FROM employees WHERE salary > ALL (SELECT AVG(salary) FROM employees GROUP BY department_id);
E.SELECT last_name FROM employees WHERE salary > ANY (SELECT MAX(salary) FROM employees GROUP BY department_id);
F.SELECT department_id FROM employees WHERE salary > ALL (SELECT AVG(salary) FROM employees GROUP BY AVG(SALARY));
多项选择题
A. SELECT TO_CHAR(2000, '$#,###.##') FROM dual;
B. SELECT TO_CHAR(2000, '$0,000.00') FROM dual;
C. SELECT TO_CHAR(2000, '$9,999.00') FROM dual;
D. SELECT TO_CHAR(2000, '$9,999.99') FROM dual;
E. SELECT TO_CHAR(2000, '$2,000.00') FROM dual;
F. SELECT TO_CHAR(2000, '$N,NNN.NN') FROM dual;
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.An error is returned.
B.You are prompted to enter a new value.
C.A report is produced that matches the first report produced.
D.You are asked whether you want a new value or if you want to run the report based on the previous value.
单项选择题
A.The DESCRIBE DEPT statement displays the structure of the DEPT table.
B.The ROLLBACK statement frees the storage space occupied by the DEPT table.
C.The DESCRIBE DEPT statement returns an error ORA-04043: object DEPT does not exist.
D.The DESCRIBE DEPT statement displays the structure of the DEPT table only if there is a COMMIT statement introduced before the ROLLBACK statement.
单项选择题
A.SELECT e.last_name, d. department_name, d.location_id FROM employees e NATURAL JOIN departments D USING department_id ;
B.SELECT last_name, department_name, location_id FROM employees NATURAL JOIN departments WHERE e.department_id =d.department_id;
C.SELECT e.last_name, d.department_name, d.location_id FROM employees e NATURAL JOIN departments d;
D.SELECT e.last_name, d.department_name, d.location_id FROM employees e JOIN departments d USING (department_id );
单项选择题
A.Once created, a sequence belongs to a specific schema.
B.Once created, a sequence is linked to a specific table.
C.Once created, a sequence is automatically available to all users.
D.Only the DBA can control which sequence is used by a certain table.
E.Once created, a sequence is automatically used in all INSERT and UPDATE statements.
多项选择题
A.You can use aggregate functions in any clause of a SELECT statement.
B.You can use aggregate functions only in the column list of the SELECT clause and in the WHERE clause of a SELECT statement.
C.You can mix single row columns with aggregate functions in the column list of a SELECT statement by grouping on the single row columns.
D.You can pass column names, expressions, constants, or functions as parameters to an aggregate function.
E.You can use aggregate functions on a table, only by grouping the whole table as one single group.
F.You cannot group the rows of a table by more than one column while using aggregate functions.