Hi Giannis, Have you use "CREATE FUNCTION asyncfn AS 'Your full class name of async function class'" or "CREATE TEMPORARY FUNCTION asyncfn AS 'Your full class name of async function class'" to create a customized function named "asyncfn" before it is used in your sql?
The error message "No match found for function signature" usually indicates that the function does not exist or the parameters do not match. Best, Shammon FY On Sun, May 7, 2023 at 2:55 PM Giannis Polyzos <ipolyzos...@gmail.com> wrote: > I can't really find any examples / docs for Flink's AsyncTableFunction and > I have a hard time getting it to work. > Is there any example you can share that just takes as input a String key > and outputs lets say a record (returned by the lookup?) > Also is not clear to me how the async happens internally. > Is the future in the eval method signature used? > > I tried implementing eval methods like: > *public final void eval(CompletableFuture<Collection<RowData>> future, > Object... keys)* > > *or * > > > *public void eval(CompletableFuture<Collection<Row>> result, String > rowkey)* > > but in both cases if I do something like > *SELECT asyncfn(accountId) from transactions;* > I get > *org.apache.calcite.sql.validate.SqlValidatorException: No match found for > function signature asyncfn(<CHARACTER>)* > > Not sure what I am missing > > Thanks, > Giannis >
