Databases - Upwork
 

  1. Question: Which of the following is the correct way to determine duplicate values?

    A
    SELECT column_duplicated, sum(*) amount FROM table_name WHERE amount > 1 GROUP BY column_duplicated

    B
    SELECT column_duplicated, COUNT(*) amount FROM table_name WHERE amount > 1 GROUP BY column_duplicated

    C
    SELECT column_duplicated, sum(*) amount FROM table_name GROUP BY column_duplicated HAVING amount > 1

    D
    SELECT column_duplicated, COUNT(*) amount FROM table_name GROUP BY column_duplicated HAVING amount > 1

    Note: Not available
    1. Report

  2. Question: Examine the query: select (2/2/4) from tab1; where tab1 is a table with one row. This would give a result of:

    A
    4

    B
    2

    C
    1

    D
    .5

    E
    .25

    F
    8

    G
    25

    Note: Not available
    1. Report

  3. Question: Which of the following commands will list the tables of the current database?

    A
    SHOW TABLES

    B
    DESCRIBE TABLES

    C
    SHOW ALL TABLES

    D
    LIST TABLES

    Note: Not available
    1. Report

  4. Question: Which of the following is not a MySQL statement?

    A
    ENUMERATE

    B
    EXPLAIN

    C
    KILL

    D
    LOAD DATA

    E
    SET

    Note: Not available
    1. Report

  5. Question: When running the following SELECT query:
    SELECT ID FROM (
    SELECT ID, name FROM (
        SELECT * 
             FROM employee
    )
);
    The error message 'Every derived table must have its own alias' appears. Which of the following is the best solution for this error?

    A
    SELECT ID FROM ( SELECT ID AS SECOND_ID, name FROM ( SELECT * FROM employee ) );

    B
    SELECT ID FROM ( SELECT ID, name AS NAME FROM ( SELECT * FROM employee ) );

    C
    SELECT ID FROM ( SELECT ID, name FROM ( SELECT * FROM employee ) AS T ) AS T;

    D
    SELECT ID AS FIRST_ID FROM ( SELECT ID, name FROM ( SELECT * FROM employee ) );

    Note: Not available
    1. Report

  6. Question: Which of the following is not a Table Storage specifier in MySQL?

    A
    InnoDB

    B
    MYISAM

    C
    BLACKHOLE

    D
    STACK

    Note: Not available
    1. Report

  7. Question: The REPLACE statement is:

    A
    Same as the INSERT statement

    B
    Like INSERT, except that if an old row in the table has the same value as a new row for a PRIMARY KEY or a UNIQUE index, the old row is deleted before the new row is inserted

    C
    There is no such statement as REPLACE

    Note: Not available
    1. Report

  8. Question: If you try to perform an arithmetic operation on a column containing NULL values, the output will be:

    A
    NULL

    B
    An error will be generated

    C
    Cannot be determined

    Note: Not available
    1. Report

  9. Question: Which of the following is the best way to insert a row, and to update an existing row, using a MySQL query?

    A
    Use MERGE statement

    B
    Use INSERT ... ON DUPLICATE KEY UPDATE statement

    C
    Use ADD UNIQUE statement

    D
    Use REPLACE statement

    Note: Not available
    1. Report

  10. Question: How will you change "Hansen" into "Nilsen" in the LastName column in the Persons Table?

    A
    UPDATE Persons SET LastName = 'Nilsen' WHERE LastName = 'Hansen'

    B
    UPDATE Persons SET LastName = 'Hansen' INTO LastName = 'Nilsen'

    C
    SAVE Persons SET LastName = 'Nilsen' WHERE LastName = 'Hansen'

    D
    SAVE Persons SET LastName = 'Hansen' INTO LastName = 'Nilsen'

    Note: Not available
    1. Report
First56789Last
/90
Copyright © 2025. Powered by Intellect Software Ltd