Casting data from message fields
You can use the CAST function to transform the data type of one value to match the data type of the other. For example, you can use the CAST function when you process generic XML messages. All fields in an XML message have character values, so if you want to perform arithmetic calculations or datetime comparisons, for example, you must convert the string value of the field into a value of the appropriate type using CAST.
About this task
When you compare an element with another element, variable or constant, ensure that the value with which you are comparing the element is consistent (for example, character with character). If the values are not consistent, the integration node generates a runtime error if it cannot provide an implicit casting to resolve the inconsistency. For details of what implicit casts are supported, see Implicit casts.
In the Example message, the field InvoiceDate contains the date of the invoice. If you want to refer to or manipulate this field, you must CAST it to the correct format first. For example, to refer to this field in a test:
IF CAST(Body.Invoice.InvoiceDate AS DATE) = CURRENT_DATE THEN
This converts the string value of the InvoiceDate field into a date value, and compares it to the current date.
Another example is casting from integer to character:
DECLARE I INTEGER 1; DECLARE C CHARACTER; -- The following statement generates an error SET C = I; -- The following statement is valid SET C = CAST(I AS CHARACTER);