# Scalar functions
<a name="sql-functions-scalar"></a>

 Scalar functions take one or more input values and returns a single output value. They are widely used in SQL (Structured Query Language) for data manipulation and retrieval, improving the efficiency of data processing tasks. 

**Topics**
+ [Null data functions](sql-functions-null.md)
+ [String functions](sql-functions-string.md)
+ [Math functions](sql-functions-math.md)
+ [Date time functions](sql-functions-date.md)
+ [Type conversion functions](sql-functions-type-conv.md)