Tagged/delimited string format - Relationship to the logical model

There are some restrictions between TDS separation types and logical model properties such as group composition and group content validation. The rules governing these options are explained in Restrictions for nesting complex types.

These rules exist to ensure the integrity of the message. A combination of separation type and group composition or group content validation must not lead to a message that is unclear to a TDS parser.

Default values

In TDS, Default values are only observed by fixed length elements:

Separation Type Use of Default values
  • Tagged Delimited
  • Tagged Fixed Length
  • Tagged Encoded Length
  • All Elements Delimited
  • Data Pattern
Default values are never observed.
  • Fixed Length
  • Fixed Length AL3
Default values are observed on output by all elements. An absent element that has no Default value defined, will cause an error on writing.
Variable Length Elements Delimited Default values are only observed by fixed length elements on output. Absent fixed length values must have a Default value available to them. An absent element that has no Default value defined, will cause an error on writing.

Related Concepts
Tagged/delimited string format
Data element separation
Tagged/delimited string format - Model integrity
Tagged/delimited string format - NULL handling
Tagged/delimited string format - Multipart messages
Tagged/delimited string format - Data conversion

Related Reference
Restrictions for nesting complex types