单项选择题
Evaluate this SQL statement:
SELECT e.EMPLOYEE_ID,e.LAST_NAME,e.DEPARTMENT_ID, d.DEPARTMENT_NAME
FROM EMPLOYEES e, DEPARTMENTS d
WHERE e.DEPARTMENT_ID = d.DEPARTMENT_ID;
In the statement, which capabilities of a SELECT statement are performed?（）
A.selection, projection, join
B.difference, projection, join
C.selection, intersection, join
D.intersection, projection, join
E.difference, projection, product
相关考题
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单项选择题
Evaluate these two SQL statements: SELECT last_name, salary , hire_date FROM EMPLOYEES ORDER BY salary DESC; SELECT last_name, salary , hire_date FROM EMPLOYEES ORDER BY 2 DESC; What is true about them?（）
A.The two statements produce identical results.
B.The second statement returns a syntax error.
C.There is no need to specify DESC because the results are sorted in descending order by default.
D.The two statements can be made to produce identical results by adding a column alias for the salary column in the second SQL statement. -
多项选择题
What are two reasons to create synonyms? （）
A.You have too many tables.
B.Your tables are too long.
C.Your tables have difficult names.
D.You want to work on your own tables.
E.You want to use another schema's tables.
F.You have too many columns in your tables. -
单项选择题
What is necessary for your query on an existing view to execute successfully?（）
A.The underlying tables must have data.
B.You need SELECT privileges on the view.
C.The underlying tables must be in the same schema.
D.You need SELECT privileges only on the underlying tables.
