Informatics Practices · Ch 1 — Querying and SQL Functions
Summary
Summary
- A Function is used to perform a particular task and return a value as a result.
- Single row functions work on a single row to return a single value.
- Multiple row (aggregate) functions work on a set of records as a whole and return a single value.
- Numeric functions perform operations on numeric values and return numeric values.
- String functions perform operations on character type values and return either character or numeric values.
- Date and time functions allow us to deal with date type data values.
- The GROUP BY clause is used to group the rows together that contain similar values in a specified column. Some of the group functions are
COUNT,MAX,MIN,AVGandSUM. …