How To Cast Using a Built-In XQuery Function

This topic describes how to use a built-in XQuery function to cast values of different data types in an update map.

Example

You can cast an element from one data type to another using a built-in XQuery cast function when:

Type promotion does not occur.
The data comes from a variable or an other source that is not a constant
A built-in function that performs the cast you want is available in the Design Palette.

To cast using a built-in XQuery function:

Click the Update Map tab.
Click the disabled element in an update block on the left.
In the expression editor, you see an expression that uses fn-bea:value() to map from the return type on the right, for example:
```
fn-bea:value($CUSTOMER/CUSTOMER_SINCE)
```
This expression represents a dateTime value coming from the return type.
Open the Design Palette
```
Window > Show View > Design Palette
```
Expand XQuery Functions, then a category (for example, Duration, Date, and Time Functions).
Drag the function you want to the expression editor (for example, fn-bea:date-from-dateTime), leaving the existing expression there.
If feasible, use the existing expression as an argument to the function, for example:
```
fn-bea:date-from-dateTime( fn-bea:value($CUSTOMER/CUSTOMER_SINCE) )
```
Here the original value is used as the $dateTime argument to fn-bea:date-from-dateTime().
Test the update map cast to make sure it works as you expect.