How to use

getRelSchemaProviders

method

in

org.apache.samza.sql.runner.SamzaSqlApplicationConfig

@Override
public Collection<RelRoot> convertDsl(String dsl) {
 // TODO: Introduce an API to parse a dsl string and return one or more sql statements
 List<String> sqlStmts = fetchSqlFromConfig(config);
 List<SamzaSqlQueryParser.QueryInfo> queryInfo = fetchQueryInfo(sqlStmts);
 SamzaSqlApplicationConfig sqlConfig = new SamzaSqlApplicationConfig(config,
   queryInfo.stream().map(SamzaSqlQueryParser.QueryInfo::getSources).flatMap(Collection::stream)
     .collect(Collectors.toSet()),
   queryInfo.stream().map(SamzaSqlQueryParser.QueryInfo::getSink).collect(Collectors.toSet()));
 QueryPlanner planner =
   new QueryPlanner(sqlConfig.getRelSchemaProviders(), sqlConfig.getSystemStreamConfigsBySource(),
     sqlConfig.getUdfMetadata());
 List<RelRoot> relRoots = new LinkedList<>();
 for (String sql: sqlStmts) {
  // when sql is a query, we only pass the select query to the planner
  SamzaSqlQueryParser.QueryInfo qinfo = SamzaSqlQueryParser.parseQuery(sql);
  if (qinfo.getSink().split("\\.")[0].equals(SamzaSqlApplicationConfig.SAMZA_SYSTEM_LOG)) {
   sql = qinfo.getSelectQuery();
  }
  relRoots.add(planner.plan(sql));
 }
 return relRoots;
}

@Override
public Collection<RelRoot> convertDsl(String dsl) {
 // TODO: Introduce an API to parse a dsl string and return one or more sql statements
 List<String> sqlStmts = fetchSqlFromConfig(config);
 List<SamzaSqlQueryParser.QueryInfo> queryInfo = fetchQueryInfo(sqlStmts);
 SamzaSqlApplicationConfig sqlConfig = new SamzaSqlApplicationConfig(config,
   queryInfo.stream().map(SamzaSqlQueryParser.QueryInfo::getSources).flatMap(Collection::stream)
     .collect(Collectors.toList()),
   queryInfo.stream().map(SamzaSqlQueryParser.QueryInfo::getSink).collect(Collectors.toList()));
 QueryPlanner planner =
   new QueryPlanner(sqlConfig.getRelSchemaProviders(), sqlConfig.getInputSystemStreamConfigBySource(),
     sqlConfig.getUdfMetadata());
 List<RelRoot> relRoots = new LinkedList<>();
 for (String sql: sqlStmts) {
  // we always pass only select query to the planner for samza sql. The reason is that samza sql supports
  // schema evolution where source and destination could up to an extent have independent schema evolution while
  // calcite expects strict comformance of the destination schema with that of the fields in the select query.
  SamzaSqlQueryParser.QueryInfo qinfo = SamzaSqlQueryParser.parseQuery(sql);
  relRoots.add(planner.plan(qinfo.getSelectQuery()));
 }
 return relRoots;
}

/**
 * For unit testing only
 */
@VisibleForTesting
void translate(SamzaSqlQueryParser.QueryInfo queryInfo, StreamApplicationDescriptor appDesc, int queryId) {
 QueryPlanner planner =
   new QueryPlanner(sqlConfig.getRelSchemaProviders(), sqlConfig.getInputSystemStreamConfigBySource(),
     sqlConfig.getUdfMetadata());
 final RelRoot relRoot = planner.plan(queryInfo.getSelectQuery());
 SamzaSqlExecutionContext executionContext = new SamzaSqlExecutionContext(sqlConfig);
 TranslatorContext translatorContext = new TranslatorContext(appDesc, relRoot, executionContext);
 translate(relRoot, sqlConfig.getOutputSystemStreams().get(queryId), translatorContext, queryId);
 Map<Integer, TranslatorContext> translatorContexts = new HashMap<>();
 translatorContexts.put(queryId, translatorContext.clone());
 appDesc.withApplicationTaskContextFactory(new ApplicationTaskContextFactory<SamzaSqlApplicationContext>() {
  @Override
  public SamzaSqlApplicationContext create(ExternalContext externalContext, JobContext jobContext,
    ContainerContext containerContext, TaskContext taskContext,
    ApplicationContainerContext applicationContainerContext) {
   return new SamzaSqlApplicationContext(translatorContexts);
  }
 });
}

/**
 * For unit testing only
 */
@VisibleForTesting
public void translate(SamzaSqlQueryParser.QueryInfo queryInfo, StreamApplicationDescriptor appDesc) {
 QueryPlanner planner =
   new QueryPlanner(sqlConfig.getRelSchemaProviders(), sqlConfig.getSystemStreamConfigsBySource(),
     sqlConfig.getUdfMetadata());
 final RelRoot relRoot = planner.plan(queryInfo.getSql());
 int queryId = 1;
 SamzaSqlExecutionContext executionContext = new SamzaSqlExecutionContext(sqlConfig);
 Map<String, SamzaRelConverter> converters = sqlConfig.getSamzaRelConverters();
 TranslatorContext translatorContext = new TranslatorContext(appDesc, relRoot, executionContext, converters);
 translate(relRoot, translatorContext, queryId);
 Map<Integer, TranslatorContext> translatorContexts = new HashMap<>();
 translatorContexts.put(queryId, translatorContext.clone());
 appDesc.withApplicationTaskContextFactory((jobContext,
   containerContext,
   taskContext,
   applicationContainerContext) ->
   new SamzaSqlApplicationContext(translatorContexts));
}