SQL statements can, intentionally or not, require the mixing of different data types in the same expression. LightDB has extensive facilities for evaluating mixed-type expressions.

In many cases a user does not need to understand the details of the type conversion mechanism. However, implicit conversions done by LightDB can affect the results of a query. When necessary, these results can be tailored by using explicit type conversion.

This chapter introduces the LightDB type conversion mechanisms and conventions. Refer to the relevant sections in Chapter 9 and Chapter 10 for more information on specific data types and allowed functions and operators.