Interview Questions

bcoz interface does not contains any initializers and constructors to initialize its data members.

- ABS(number)

Returns the absolute positive value of an expression.
Syntax:
ABS(expression)
Example:
SELECT ABS(-1.0), ABS(0.0), ABS(1.0)
Output:
1.0    .0    1.0

- CEIL(number)

Returns the smallest integer greater than, or equal to, the specified numeric expression.
Syntax:
CEILING(expression)
Example:
SELECT CEILING($223.45), CEILING($-223.45), CEILING($0.0)
Output:
224.00    -223.00        0.00

- FLOOR(number)

Returns the largest integer less than, or equal to, the specified numeric expression.
Syntax:
FLOOR(expression)
Example:
SELECT FLOOR($223.45), CEILING($-223.45), CEILING($0.0)
Output:
223.00      -224.00        0.00

- MOD(number, divisor)

Returns the remainder of the division from 2 integer values.
Syntax:
MOD(dividend, divisor)
Example:
SELECT MOD(20,3)
Output:
2

- POWER(number, power)

Returns the exponential value for the numeric expression.
Syntax:
POWER(number, power)
Example:
SELECT POWER(2.0, 3.0)
Output:
8.0

- SIGN(number)

Returns the sign i.e. positive or negative value for the numeric expression. It returns -1 for negative expressions, a value of 0 for zero
Syntax:
SIGN(number)
Example:
SELECT SIGN(4)
Output:
1

- ROUND(number, precision)

Returns the numeric value rounded off to the next value specified.
Syntax:
ROUND(number, number of places)
Example:
SELECT ROUND(1.3456, 2)

- SQRT(number)

Returns the square root value of the expression.
Syntax:
SQRT(number)
Example:
SELECT SQRT(4.0)
Output:
2.0

- TRUNC(number, precision)

Returns a numeric value that truncate to the specific places
Syntax:
TRUNCATE(number,places)
Example:
SELECT TRUNCATE(1.3456, 2)
Output:
1.34

A foreign key is a reference to another table. It is used to establish relationships between tables. For example, relationship between employee and professor table. One employee can have multiple professors. The Primary key of employee becomes foreign key of professor.
Example:
create table employee ( id number NOT NULL, professor_id NOT NULL, Name varchar(200) Constraint prim_id Foreign key(id) references professor(professor_id) );

.NET does not support multiple inheritance directly because in .NET, a class cannot inherit from more than one class. .NET supports multiple inheritance through interfaces.

DriverManager is a class in java.sql package. It is the basic service for managing a set of JDBC drivers.

By default, primary key creates a clustered index on the column, whereas a unique key creates a non clustered index by default.

As far PHP concern it only support single Inheritance in scripting. we can also use interface to achieve multiple inheritance.

The Internal Rate of Return (IRR) is defined as the measure of an investment’s rate of return. It is also called the discounted cash flow rate of return.