In Iguana, errors are automatically logged if a database entry being processed by a From Database channel source component has all of its key fields set to NULL. This means that the message will not be processed, since all key fields must have non-NULL values for data to be inserted or updated. The only exception to this rule is if all fields for a given row are NULL. Consequently, setting all fields for a row to NULL causes three things to occur:

• The message will be processed successfully; but
• No error will be generated, since there is no data to insert or update; and
• No row is added or updated.

	Leaving a key field blank when at least one other field contains a value will cause an error to be generated.