Examples with ResultSetProcessorImpl org.hibernate.loader.plan.exec.process.internal.ResultSetProcessorImpl used on opensource projects

Example 1 with ResultSetProcessorImpl

use of org.hibernate.loader.plan.exec.process.internal.ResultSetProcessorImpl in project hibernate-orm by hibernate.

the class AbstractLoadQueryDetails method generate.

/**
 * Main entry point for properly handling the FROM clause and and joins and restrictions
 */
protected void generate() {
    // There are 2 high-level requirements to perform here:
    // 1) Determine the SQL required to carry out the given LoadPlan (and fulfill
    // {@code LoadQueryDetails#getSqlStatement()}).  SelectStatementBuilder collects the ongoing efforts to
    // build the needed SQL.
    // 2) Determine how to read information out of the ResultSet resulting from executing the indicated SQL
    // (the SQL aliases).  ReaderCollector and friends are where this work happens, ultimately
    // producing a ResultSetProcessor
    final SelectStatementBuilder select = new SelectStatementBuilder(queryProcessor.getSessionFactory().getDialect());
    // LoadPlan is broken down into 2 high-level pieces that we need to process here.
    // 
    // First is the QuerySpaces, which roughly equates to the SQL FROM-clause.  We'll cycle through
    // those first, generating aliases into the AliasContext in addition to writing SQL FROM-clause information
    // into SelectStatementBuilder.  The AliasContext is populated here and the reused while process the SQL
    // SELECT-clause into the SelectStatementBuilder and then again also to build the ResultSetProcessor
    applyRootReturnTableFragments(select);
    if (shouldApplyRootReturnFilterBeforeKeyRestriction()) {
        applyRootReturnFilterRestrictions(select);
        // add restrictions...
        // first, the load key restrictions (which entity(s)/collection(s) do we want to load?)
        applyKeyRestriction(select, getRootTableAlias(), keyColumnNames, getQueryBuildingParameters().getBatchSize());
    } else {
        // add restrictions...
        // first, the load key restrictions (which entity(s)/collection(s) do we want to load?)
        applyKeyRestriction(select, getRootTableAlias(), keyColumnNames, getQueryBuildingParameters().getBatchSize());
        applyRootReturnFilterRestrictions(select);
    }
    applyRootReturnWhereJoinRestrictions(select);
    applyRootReturnOrderByFragments(select);
    // then move on to joins...
    applyRootReturnSelectFragments(select);
    queryProcessor.processQuerySpaceJoins(getRootQuerySpace(), select);
    // Next, we process the Returns and Fetches building the SELECT clause and at the same time building
    // Readers for reading the described results out of a SQL ResultSet
    FetchStats fetchStats = null;
    if (FetchSource.class.isInstance(rootReturn)) {
        fetchStats = queryProcessor.processFetches((FetchSource) rootReturn, select, getReaderCollector());
    } else if (CollectionReturn.class.isInstance(rootReturn)) {
        final CollectionReturn collectionReturn = (CollectionReturn) rootReturn;
        if (collectionReturn.getElementGraph() != null) {
            fetchStats = queryProcessor.processFetches(collectionReturn.getElementGraph(), select, getReaderCollector());
        }
    // TODO: what about index???
    }
    if (fetchStats != null && fetchStats.getJoinedBagAttributeFetches().size() > 1) {
        final List<String> bagRoles = new ArrayList<>();
        for (CollectionAttributeFetch bagFetch : fetchStats.getJoinedBagAttributeFetches()) {
            bagRoles.add(bagFetch.getCollectionPersister().getRole());
        }
        throw new MultipleBagFetchException(bagRoles);
    }
    LoadPlanTreePrinter.INSTANCE.logTree(loadPlan, queryProcessor.getAliasResolutionContext());
    this.sqlStatement = select.toStatementString();
    this.resultSetProcessor = new ResultSetProcessorImpl(loadPlan, queryProcessor.getAliasResolutionContext(), getReaderCollector().buildRowReader(), shouldUseOptionalEntityInstance(), isSubselectLoadingEnabled(fetchStats));
}