IT Trainer Questions

The Riddle itself has the Answers.

What is a 4 letter word

Yet is written in 3 letters

Everything is written with 9 letters

Then with 4 letters

Rarely has 6 letters

Never is written in 5 letters.

As the arguments C and E states that other companies are on the losing end with this scheme, it is the only appropriate answer to this question.

Mushroom.

Land is considered as an important resource because it is useful in producing many things. For example, in agriculture, land is used for cultivating the crop, in industrial use, it is used for constructing factories and to make products that we use.

A promise. 

The Promise made to somebody by you can be break but you cannot touch it.

There are two IP address assigned to each device on a Wi-Fi network.

An Internal (Private) and an External (Public) IP address.

Internal IP address is used for communication between Your computer and a smartphone or whatever devices that are connected to that Wifi network. This is unique for each. If they are same the system cannot differentiate between each device.

While, the External IP address is that visible to the the internet - the websites, the internet connected Apps so on. By default, Routers with NAT (all routers today have it) assign same Public IP address to all devices under its network.

MAC - Media Access Control, address is a globally unique identifier assigned to network devices, and therefore it is often referred to as hardware or physical address.

MAC addresses are 6-byte (48-bits) in length, and are written in MM:MM:MM:SS:SS:SS format.

A Subquery or Inner query or a Nested query is a query within another SQL query and embedded within the WHERE clause.

Subqueries are most frequently used with the SELECT statement. The basic syntax is as follows::

SELECT column_name [, column_name ]
FROM table1 [, table2 ]
WHERE column_name OPERATOR
(SELECT column_name [, column_name ]
FROM table1 [, table2 ]
[WHERE])

A subquery is used to return data that will be used in the main query as a condition to further restrict the data to be retrieved.

Subqueries can be used with the SELECT, INSERT, UPDATE, and DELETE statements along with the operators like =, <, >, >=, <=, IN, BETWEEN, etc.

There are a few rules that subqueries must follow −

1. Subqueries must be enclosed within parentheses.

2. A subquery can have only one column in the SELECT clause, unless multiple columns are in the main query for the subquery to compare its selected columns.

3. An ORDER BY command cannot be used in a subquery, although the main query can use an ORDER BY. The GROUP BY command can be used to perform the same function as the ORDER BY in a subquery.

4. Subqueries that return more than one row can only be used with multiple value operators such as the IN operator.

5. The SELECT list cannot include any references to values that evaluate to a BLOB, ARRAY, CLOB, or NCLOB.

6. A subquery cannot be immediately enclosed in a set function.

7. The BETWEEN operator cannot be used with a subquery. However, the BETWEEN operator can be used within the subquery.