Hi, Julian. Thanks for your explanation and suggestions. I will take it into consideration.
Best, Shengkai Julian Hyde <[email protected]> 于2021年4月21日周三 上午12:19写道： > If there are some major improvements, consider proposing them as a > Calcite change. You'd have to figure out whether your new message is > an improvement in EVERY case where we currently throw "Non-query > expression encountered in illegal context". That error happens in a > tricky parser context, where we can't figure out whether we're looking > at a query or an expression. For example, something like > > SELECT * FROM t > WHERE x IN (((FOO BAR))) > > Note that where FOO occurs you could also have SELECT (because a > sub-query could happen here) and you could also have an expression > such as "1 + 2". > > Maybe the solution is to change the parser. If you know you are > parsing a top-level statement (DDL command or query) and an expression > is not possible you can give a better error. > > Julian > > On Tue, Apr 20, 2021 at 7:51 AM Shengkai Fang <[email protected]> wrote: > > > > Hi, devs. > > > > Recently I am working around to improve the exception messages when using > > parser to parse meaningless statement. For example, > > > > ``` > > parser.parse("INVALID COMMAND"); > > ``` > > we will get the cause > > > > ``` > > org.apache.flink.table.api.SqlParserException: SQL parse failed. > Non-query > > expression encountered in illegal context > > ``` > > > > I think `Unsupprorted input statement` is much more straighforward for > usrs > > to understand. > > > > So my goal is to find how we can define the user-defined exception > > message, i.e. define exception message for > > `CalciteResource#illegalNonQueryExpression`. > > > > After the dig, I find the `org.apache.calcite.runtime.Resources#create` > > will try to load the content of `CalciteResource.properties` to define > the > > exception message. If the `CalciteResource.properties` is not found or > not > > found the key in the file, it will use the anotation as the exception > > message. The logic is located at > > `org.apache.calcite.runtime.Resources$Inst#raw` > > > > My solution to solve the problem is to override the > > CalciteResources.properties and add the expected exception message in the > > new CalciteResources.properties. > > > > However, the new CalciteResources.properties doesn't `extend` the old > > CalciteResources.properties. That is we lose other error messages that > are > > defined in the origin CalciteResources.properties. Do we need to copy the > > origin content into the new file and modify the message we want to > modify? > > > > Look forward to your feedback. > > > > Best, > > Shengkai >
