Technology Questions

All the features of C are similiar to C++ except some features, such as polymorphism, operator overloading which are supported in C++ but not in C language.

Both C and C++ language is similiar in their functionality but C++ provides with more tools and options.

By use of %ISOPEN status variable.

Plug and Play is a technology wherein hardware components that are installed on PCs using Microsoft operating system are immediately recognized and made usable. This means that the drivers necessary to make it work are already available on the operating system package.

Error-first callbacks are used to pass errors and data as well. You have to pass the error as the first parameter, and it has to be checked to see if something went wrong. Additional arguments are used to pass data.

fs.readFile(filePath, function(err, data) {
if (err) {
// handle the error, the return is important here
// so execution stops here
return console.log(err)
}
// use the data object
console.log(data)
})

Fires when oracle forms first marks a record as an insert or an update. The trigger fires as soon as oracle forms determines through validation that the record should be processed by the next post or commit as an insert or update. Generally occurs only when the operators modifies the first item in the record, and after the operator attempts to navigate out of the item.

The C++ language provides a single global namespace.Namespaces allow to group entities like classes, objects and functions under a name.

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