Mathematical operators
This article is about mathematical operators as part of the SQL syntax that USoft supports.
Mathematical operators
A mathematical operator applies a basic arithmetic calculation to the values represented to its left and right.
Syntax
*value math-operator value*
The following 4 mathematical operators are supported:
+ | addition |
- | subtraction |
* | multiplication |
/ | division |
Parentheses may be used to indicate order of evaluation.
( 2 / 5 ) * 100 | 2 is first divided by 5. The outcome is multiplied by 100. The outcome is 40. |
If you omit parentheses, multiplication and dividion take precedence over addition and subtraction, but USoft recommends you ALWAYS write parentheses for readability.
Calculations with non-number values
Mathematical operators are mostly used with number values, where they take their full arithmetic meaning. On some RDBMSs, you can add days to a date by adding a numerical value, where 1 = a 24-hour day. Likewise, you can use the '-' operator to subtract 2 date values. The result is the time difference, expressed as a number, where 1 = a 24-hour day. USoft recommends that you use functions for date calculations instead.
On MS SQL Server, the '+' operator may be used to concatenate 2 string values. This is RDBMS-specific. USoft recommends you use the equivalent CONCAT function if you can. It has the advantage of being convertible, but the drawback that it takes 2 input values only.