Another usage of expressions is the Grouping, Filtering, and
It is important to understand that these operations perform
comparison/combination between the results of the evaluation of the used
expression. These are valid only between items of the same data type.
If the data types do not match, you must explicitly convert the data type
that the expression evaluates to by using
Here are the cases when you need to use conversion:
- Writing filter expressions that compare values of different data types.
- Writing sort expressions that combine fields of different data types.
- Writing group expressions that combine fields of different data types.
- Converting a value retrieved from the data source from one data type to a different data type.