What is a Flat File Schema?

A flat file schema is the blueprint that contains the instructions for parsing or creating a flat file and is created as a namespace element in the Integration Server. This blueprint details the structure of the document, including delimiters, records, and repeated record structures. A flat file schema also acts as the model against which you can validate an inbound flat file.

A flat file schema consists of hierarchical elements that represent each record, field, and subfield in a flat file. Each element is a record, composite, or field. Additionally, each element is either a reference or a definition. A definition is an element that is defined in the flat file schema. A reference is an element that is defined in a flat file dictionary and referenced from the flat file schema. You configure each element with the necessary constraints.

Flat file schemas contain information about the constraints at the document, record, and field levels of flat files. A flat file schema can define three types of constraints:

Structural constraints describe the sequence of records, composites, and fields in a flat file. For example, a flat file schema might describe an address record that consists of a Street Address field, followed by a City field, State field, and ZIP Code field. You define structural constraints for each parent element (an element that contains other records, composites, or fields) in the flat file schema.

Content type constraints describe the possible values or minimum/maximum values for elements in a flat file. For example, the State field might have a content constraint specifying that its value must be exactly two digits. These types of constraints are referred to as validators.

Conditional constraints describe the valid combinations of fields and subfields allowed in records and composites. For example, you can use the Required (R) conditional validator to require that at least one of the specified fields be present.

When validating an inbound flat file, Integration Server compares the records, composites, and fields in a flat file with the constraints described for those records and fields in the flat file schema. An inbound flat file is considered valid when it complies with the constraints outlined in its related flat file schema. For more information about data validation, see Validation Errors.