Matt Burgess created NIFI-5419: ---------------------------------- Summary: Improve alias handling in DB Fetch processors Key: NIFI-5419 URL: https://issues.apache.org/jira/browse/NIFI-5419 Project: Apache NiFi Issue Type: Improvement Components: Extensions Reporter: Matt Burgess
Often the DB Fetch processors (GenerateTableFetch, QueryDatabaseTable, etc.) ask the configured Database Type (aka DB adapter) for DB-specific things such as generated SQL for SELECT, INSERT, etc. However GenerateTableFetch (as an example), when it fetches the COUNT and MAX for a specified Maximum Value Column, hard-codes the alias as the following: {{SELECT COUNT(*), MAX(myColumn) myColumn}} This works for many databases in many situations, but still can result in errors. For example, in PostgreSQL if the column name is a reserved word, then the above format will not work; the alias needs an explicit AS, and perhaps even quoting. This may be as simple as hard-coding the AS keyword into the query, but we'd need to test this on all databases we wish the processor to work with. If it is a DB-specific issue, then we'd need to move the logic into the DB Adapters and have the fetch processors call to the adapter to get the correct clause. -- This message was sent by Atlassian JIRA (v7.6.3#76005)