output field name: Names of the configured fields.
type: field type
date format: If the field type is DATE, TIME, or TIMESTAMP, you need to specify the time format. If the field type is neither of them, the time format is invalid. The example time format is yyyyMMdd HH:mm:ss.
length: Field value length. If the actual field value is excessively long, the value is cut based on the configured length. When type is set to CHAR, spaces are added to the field value for supplement if the actual field value length is less than the configured length. When type is set to VARCHAR, no space is added to the field value for supplement if the actual field value length is less than the configured length.
constant value: Constant value of the correct type.
