[Java][FlightRPC] Handle binding parameters when server can't provide the expected type
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- Java
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Descrição
### Describe the enhancement requested
Based on apache/arrow-java#156, we need to support the case where the server can't specify the expected type of a given parameter.
> Not all servers can always provide an accurate type for bind parameters. What should we do there? Note that ADBC uses NA/NullType as a wildcard/placeholder type here. This isn't specified in Flight SQL itself, but perhaps we could adopt that convention as well.
Proposal:
- When the server doesn't know the type of any of the parameters, it can just set the parameter schema to `null` (or alternatively, an empty schema).
- When the server doesn't know the type of only some of the parameters, it can just set the respective Field to `NullType`.
- Before we start binding values, we transform the `preparedStatement.getParameterSchema()` based on the types of the given `TypedValues`. If the Schema is empty/null, we create every Field for the schema based on the TypedValue type. Otherwise, we replace all NullType fields with a Field based on the TypedValue.
The only potential drawback I see with this approach is that NullTypes can't be used for parameters. That being said, I can't really think of a case why one would want to do that.
### Component(s)
Java
Guia de contribuição
Direção de pesquisa
Comece rastreando a associação de prepared statements do FlightRPC desde preparedStatement.getParameterSchema() passando pelos TypedValues usados antes da associação. Verifique o tratamento de um schema null ou vazio e de campos NullType individuais, com a conclusão sendo exibida quando cada campo do schema de parâmetros é derivado do tipo TypedValue correspondente.
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Avaliação
- Stack de tecnologia
- java
- Domínio
- api
- Tipo de issue
- Funcionalidade
- Dificuldade
- 4/5
- Tempo estimado
- 3-5 dias
- Status de atividade
- Estagnada
- Clareza
- Razoavelmente clara
- Facilidade para iniciantes
- 45/100