Technology Questions

Q:

What is the managed execution process?

Answer

Managed execution process is a process where CLR executes the managed code. The steps involved in this process are:



  1.  Choosing the right compiler

  2.  Compiling the code to MSIL. This also generates the required metadata.

  3.  Compile the MSIL ode to native machine code.

  4. Executing the code with the variety of services available

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Subject: .NET

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Q:

What are aggregate functions in SQL? What are those functions?

Answer

Aggregate functions in SQL are used to perform calculation on data. These functions are inbuilt in SQL and return a single value.

SUM( )



SUM function returns the sum or addition of all NOT NULL values of a column. For e.g. I have a Table employee with the fields id, name, salary and I want the sum of all salaries, I can use SUM function as shown
SELECT SUM(emp_salary) from employee;
Hence, if my column emp_salary has values 20,000, 22,000, 21,000; the output will be 63,000

AVG( )


 
AVG function returns the average of all NOT NULL values of a column. For e.g. I have a Table employee with the fields id, name, salary and I want the average of all salaries, I can use AVG function as shown
SELECT AVG(emp_salary) from employee;
Hence, if my column emp_salary has values 20,000, 22,000, 21,000; the output will be 21,000

COUNT( )



COUNT function returns the number of rows or values of a table. For e.g. I have a Table employee with the fields id, name, salary and I want the count of all rows, I can use COUNT function as shown
SELECT COUNT(*) from employee;

Max ( ) and Min ( )



MAX function returns the largest value of a column in a table. For e.g. I have a Table employee with the fields id, name, salary and I want the maximum salary of an employee, I can use MAX function as shown
SELECT MAX(emp_salary) from employee;
Hence, if my column emp_salary has values 20,000, 22,000, 21,000; the output will be 22,000



MIN function returns the smallest value of a column in a table. For e.g. I have a Table employee with the fields id, name, salary and I want the minimun salary of an employee, I can use MIN function as shown
SELECT MIN(emp_salary) from employee;
Hence, if my column emp_salary has values 20,000, 22,000, 21,000; the output will be 20,000

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Subject: Oracle

0 3204
Q:

Write code snippet to retrieve IMEI number of Android phone?

Answer

TelephonyManager class can be used to get the IMEI number. It provides access to information about the telephony services on the device.


Code


        TelephonyManager mTelephonyMgr = (TelephonyManager)


        getSystemService(Context.TELEPHONY_SERVICE);


        String imei = mTelephonyMgr.getDeviceId();

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Q:

Does Java support multiple inheritance?

Answer Java doesn't support multiple inheritance.
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Subject: Java

0 3193
Q:

What’s the special meaning of __sleep and __wakeup?

Answer __sleep returns the array of all the variables than need to be saved, while __wakeup retrieves them.
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Subject: PHP

0 3191
Q:

EXPLAIN has output with MATCHCOLS = 0. What does it mean?

Answer

a nonmatching index scan if ACCESSTYPE = 1


 

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0 3188
Q:

Why SELECT * is not preferred in embedded SQL programs?

Answer

- If the table structure is changed ( a field is added ), the program will have to be modified.


- Program might retrieve the columns which it might not use, leading on I/O over head.


- The chance of an index only scan is lost.

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Q:

What is C++

Answer

C++ is created by Bjarne Stroustrup of AT&T Bell Labs as an extension of C, C++ is an object-oriented computer language used in the development of enterprise and commercial applications. Microsoft’s Visual C++ became the premier language of choice among developers and programmers.

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Subject: C++

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