sqrt()

We can get square root of any number by using sqrt function, here are some examples.

select sqrt(16); // output is 4
select sqrt(20); // output is 4.47213595499958

For negative number we will get NULL output

select sqrt(-25); // output is NULL

Example of sqrt function with update query

We know how to find out hypotenuse of a right angle triangle.

H2 = A2 + B2;
H= Square root of (A2 + B2) ;

We will create one UPDATE query by using MySQL pow function.
Here it is

update sql_sqrt set H=sqrt(pow(A,2) + pow(B,2))

This will update the table with value of hypotenuse . Here is the PHP code to update the table.

require 'config.php'; // Database connection
$sql=$dbo->prepare("update sql_sqrt set H=sqrt(pow(A,2) + pow(B,2))");
if($sql->execute()){
echo "Successfully updated H";
}// End of if profile is ok
else{
print_r($sql->errorInfo()); // if any error is there it will be posted
$msg=" Database problem, please contact site admin ";
}



Download SQL dump file of this table

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