SQL Functions

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