SQL has many built-in functions for performing calculations on data.
SQL Aggregate Functions
SQL aggregate functions return a single value, calculated from values in a column.
Useful aggregate functions:
- AVG() – Returns the average value
- COUNT() – Returns the number of rows
- FIRST() – Returns the first value
- LAST() – Returns the last value
- MAX() – Returns the largest value
- MIN() – Returns the smallest value
- SUM() – Returns the sum
SQL Scalar functions
SQL scalar functions return a single value, based on the input value.
Useful scalar functions:
- UCASE() – Converts a field to upper case
- LCASE() – Converts a field to lower case
- MID() – Extract characters from a text field
- LEN() – Returns the length of a text field
- ROUND() – Rounds a numeric field to the number of decimals specified
- NOW() – Returns the current system date and time
- FORMAT() – Formats how a field is to be displayed