Details
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Improvement
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Status: Resolved
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Major
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Resolution: Fixed
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None
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None
Description
Currently, OTHER and SQLXML JDBC types are not supported by the database processors. When the processor(s) try to create a schema, it does not recognize these types and will fail. For example, this happens with PostgreSQL's JSONB and XML types, respectively.
The meaning of OTHER is "the SQL type is database-specific and gets mapped to a Java object that can be accessed via the methods getObject and setObject." Since they are Java Objects, we could represent them as Strings in the schema and use the value of toString(). This doesn't allow us to represent the JSON fields as a nested record, but we don't have enough information per se, as an OTHER value could be anything. Perhaps in a future improvement we could try to parse the object as JSON, and continue if successful. However the schema currently has to be determined beforehand, so I'm not sure if that would work.
For SQLXML, we can use the SQLXML interface to get at the String or even an InputStream, and since we know it's XML, we could parse it into records the same way XMLRecordReader does. However that would/should involve some refactor, to get the common utilities/methods into something like a nifi-xml-record-utils package. Also for this Jira it would be inconsistent with the handling of JSON fields (if reported as type OTHER). This might make a good companion Jira to the aforementioned one, to try and change JSON/XML fields into nested records.
I verified these types with PostgreSQL's JSON, JSONB, and XML types, as well as MySQL's JSON type. Oracle's XMLTYPE returns a different code (2007), and I couldn't find a way to set the connection property to return SQLXML instead. Even with that, you have to add two additional JARs to the classpath, and in my experiments it didn't seem to work when I added them to the Driver Resources property. Apache Derby doesn't have either type so I wasn't able to write unit tests to illustrate this.
This Jira proposes to add support for OTHER and SQLXML JDBC types to the database processors, interpreting their values as Strings.
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