Online database with answers to the test, 26 questions

Test items for the discipline "Databases» № 2, 26 questions.



Question 1. The operator, containing proposals in the following order ...

SELECT

WHERE ...

HAVING ...

ORDER BY ...

1. - inadmissible as WHERE and HAVING clause can not be used simultaneously in the same sentence;

2. - say;

3. - say on the composition of the proposals, but the order is wrong suggestions;

4 - is unacceptable, as there is no mandatory offer FROM (50%);

5. - is unacceptable, as the HAVING clause can not be used without the offer of GROUP BY ... (50%)




Question 2. The SELECT statement allows you to ...

1. - to select data from one or more tables and display them on the screen;

2. - to create tables;

3. - The correct data;

4. - delete the selected entry.



Question 3. The scheme of relationship:

Client (ID client name of the client, № branch, № account balance).

Select branches that have fewer than 10 clients.

1. - SELECT FROM customer №filiala

GROUP BY № branch

HAVING COUNT (*) <10;

2. - SELECT FROM customer №filiala

WHERE COUNT (ID) <10;

3. - SELECT FROM customer №filiala

HAVING COUNT (ID) <10;

4. - SELECT FROM customer №filiala

WHERE № accounts <10;


Question 4. The scheme of relations branch number

Client (ID client name of the client, № branch, № account balance).

Count the number of customers who have accounts on the rest of the branch №3 0

1. - SELECT ID FROM customer

WHERE remainder = 0 AND №filiala = 3;

2. - SELECT * FROM customer

GROUP BY remainder = 0;

3. - SELECT COUNT (*) FROM customer

WHERE remainder = 0 AND №filiala = 3;

4. - SELECT ID FROM customer

HAVING remainder = 0 AND №filiala = 3;


Question 5. The SQL language is designed to work with ...

1 - The hierarchical data model;

2 - The network data model;

3. - relational data model;

4. - object data model.



Question 6. FROM clause SQL SELECT statement sets ...

1 - The list of source tables;

2. - A list of initial forms;

3 - The initial list of attributes;

4. - A list of aliases.



Question 7. WHERE clause query SQL SELECT statement sets ...

1 - The condition of selection lines (50%);

2 - The condition of selection fields;

3 - The condition of selection of the data set;

4. - join condition tables (50%)



Question 8. In HAVING SQL SELECT statement specified ...

1 - The conditions of selection of groups;

2 - The conditions of sorting strings;

3 - The terms of the selection lines;

4 - The conditions of selection of columns.



Question 9. aggregate functions in SQL are

1. - Count (20%);

2. Sum (20%);

3. Avg (20%);

4. Min (20%);

5. Max (20%);

6. Product;

7. - Division.


Question 10. In SQL subqueries can be as follows ...

1 - scalar (33%);

2. - deferred;

3. - string (33%);

4. - table (34%);

5 - components.

Question 11. SQL scalar subquery returns ...

1. - one line;

2 - the same value;

3 - a single table;

4 - a single number.


Question 12. The SELECT statement with a subquery can contain the phrase ...

1. - ALL (50%);

2. - EXISTS (50%);

3. - DIVISION;

4. - PRODUCT.


Question 13. What operation lets you combine the results of multiple queries?


1. UNION;

2. RIGHT JOIN;

3. LEFT JOIN;

4. - MULTIPLY.


Question 14. The scheme of the relationship:

Client (ID client name of the client, № branch, № account balance).

You must define the account with the highest residues. Choose the correct statement.

1. - SELECT * FROM customer

WHERE residue = (SELECT MAX (balance)

FROM customer);

2. - SELECT MAX (residue) FROM customer;


3. - SELECT * FROM customer

WHERE remainder = MAX (balance)


4. - SELECT * FROM cu