Where relational databases have formal schemas, keys, and datatypes, REST datasources have many variations. In a REST data source, JSON-formatted data might have a JSON map that describes the structure of the data, but often mapping the columns in a REST datasources requires manual intervention to define primary keys and relationships of nested objects and arrays. Those variations are discussed in the topic Mapping REST Service metadata.

Note: Using the sample: To load the REST Connectivity sample, choose the menu item Help > Samples. Select REST Connectivity, and then click Done. Follow the Import dialog to bring the sample into your workspace. The REST Datasource is predefined in the sample to specify the data types, table and column names, and the join.
Let's get one set of rates from our sample REST Datasource by entering its URL with one parameter in a browser:
https://bj36i9ki66.execute-api.us-east-2.amazonaws.com/prod/ReimbursementRate?procedureCode=B5120ZZ
That returns:


The URL connected to the REST server that enables query filtering such that the connection returned only the results that matched the parameter value.
The sample has some complexity. You can see that the REST source data has two rates for a procedureCode. You have to consider then that there could be many rates for one code, differentiated by applicable dates. The transformation to a relational way of thinking looks like this:


This pattern shows that the REST data was interpreted as two tables related through the procedureCode. To ensure uniqueness for the primary key an incrementing integer value is added to key. Now it will be easier to define the REST Datasource in a Corticon Vocabulary. For more information, see Advanced REST Datasource Topics.

When a REST Service exposes a schema, its metadata can be imported into Corticon Studio to refine and complete the mappings between the Vocabulary and the metadata. The REST Service connection will make best-efforts to discover the REST schema. You can edit the schema definitions and tune the mapping of the REST data structure to the Vocabulary.

In the Vocabulary editor with a REST Service connection established, select the Vocabulary root, and then select the tab of the Datasource connection metadata you want to import.

As REST data sources are not as strictly defined as relational databases, the mapping of REST Datasources will likely require manual intervention to establish the primary keys and associations in the REST metadata. For more information, see the advanced topics Mapping REST Service metadata and How to define associations in REST Service metadata