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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:

1. Click the Update Map tab.
2. 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.

3. Open the Design Palette

   Window > Show View > Design Palette

4. Expand XQuery Functions, then a category (for example, Duration, Date, and Time Functions).
5. Drag the function you want to the expression editor (for example, fn-bea:date-from-dateTime), leaving the existing expression there.
6. 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().

7. Test the update map cast to make sure it works as you expect.

See Also

Concepts

• Understand Mappings with Different Data Types

How To

• Cast Using a Custom XQuery Function

• Test an Update Map Cast

Other Resources

• XQuery Tutorial at W3Schools