SQL SQRT() function

SQL SQRT function

The SQRT function is used to calculate the square root of any value. You can calculate the square root of any value using a SELECT statement like this:

    SQL>  select SQRT(16);
    +----------+
    | SQRT(16) |
    +----------+
    | 4.000000 |
    +----------+
    1 row in set (0.00 sec)

What you see here is floating points, because SQL calculates the square root in the floating point type.

You can also use the SQRT function to calculate the square root of records in the table. For a deeper understanding of SQRT functions, consider the employee_tbl table, which is recorded as follows:

    SQL> SELECT * FROM employee_tbl;
    +------+------+------------+--------------------+
    | id   | name | work_date  | daily_typing_pages |
    +------+------+------------+--------------------+
    |    1 | John | 2007-01-24 |                250 |
    |    2 | Ram  | 2007-05-27 |                220 |
    |    3 | Jack | 2007-05-06 |                170 |
    |    3 | Jack | 2007-04-06 |                100 |
    |    4 | Jill | 2007-04-06 |                220 |
    |    5 | Zara | 2007-06-06 |                300 |
    |    5 | Zara | 2007-02-06 |                350 |
    +------+------+------------+--------------------+
    7 rows in set (0.00 sec)

Now, suppose you want to get the square root daily_typing_pages in each record, you can do so with the following command:

    SQL> SELECT name, SQRT(daily_typing_pages)
        -> FROM employee_tbl;
    +------+--------------------------+
    | name | SQRT(daily_typing_pages) |
    +------+--------------------------+
    | John |                15.811388 |
    | Ram  |                14.832397 |
    | Jack |                13.038405 |
    | Jack |                10.000000 |
    | Jill |                14.832397 |
    | Zara |                17.320508 |
    | Zara |                18.708287 |
    +------+--------------------------+
    7 rows in set (0.00 sec)