Access to relational databases with WinCC Unified

How to access relational databases in WinCC Unified? ๐Ÿ‘€ย 
๐Ÿ‘‰ Last night I developed a GraphQL Custom Web Control …
๐ŸŒŸ With that and Hasura it is possible to read and write relational data.
๐Ÿ‘‰ Sources are here … not yet well documented ๐Ÿ˜Ž …

Short Demo