What are SQL Functions
Functions are very powerful feature of SQL. Functions can be used to perform
- Perform some calculation on data ( table data).
- Format date and number for display.
- Conversion of column data types.
- Manipulate output of multiple rows
SQL functions accept arguments and return a value.
Types of SQL Function
Single row as the name suggests operates only on single row and returns one result per row.
Multiple row functions operate on group of rows and returns one result per group of rows.
Hence, also known as Group Functions.
Single Row Functions
Different types of Single Row Function are:
Character Functions: Accepts character input and can return char or number values.
Number Functions: Accepts number return number.
Date Functions: Operates on Date values.
Conversion Functions: Convert value from one data type to another.
General Functions: NVL, NVL2,NULLIF,COALESCE,CASE,DECODE.
