add capability to log query parameters (bindings) values

[62mkv]

Feature Request

Describe the solution you'd like

I'd like to be able to specify logging level (say, io.r2dbc.postgresql.PARAM) which, when set to DEBUG or TRACE, would enable logging of parameters.

Describe alternatives you've considered

r2bc-proxy is an alternative, but seems to be a big overhead for such a simple use-case

Teachability, Documentation, Adoption, Migration Strategy

A mention in the README should suffice as a documentation

[mp911de]

We do not record parameter values in a canonical format that is suitable for logging. When calling bind(…), we run the bind value through the codec and the result is a Publisher<ByteBuf>. Therefore, we cannot really print any parameters during the execution.

We could add trace logging to the bind methods so that parameters get logged at the time of their binding.

[62mkv]

that would be great!

[mp911de]

Feel free to submit a pull request.

[ttddyy]

FYI, with r2dbc-proxy, you can do something like this:

MethodExecutionInfoFormatter formatter = new MethodExecutionInfoFormatter().addConsumer((execInfo, sb) -> {
  sb.append("params=");
  sb.append(StringUtils.arrayToCommaDelimitedString(execInfo.getMethodArgs()));
});

ConnectionFactory proxyConnectionFactory = 
  ProxyConnectionFactory.builder(connectionFactory)
    .listener(new LifeCycleListener() {
      @Override
      public void beforeBindOnStatement(MethodExecutionInfo methodExecutionInfo) {
        logger.info(formatter.format(methodExecutionInfo));
      }
      @Override
      public void beforeBindNullOnStatement(MethodExecutionInfo methodExecutionInfo) {
        logger.info(formatter.format(methodExecutionInfo));
      }
    })
    .build();