Examples with SubqueryBuilderListenerImpl com.blazebit.persistence.impl.SubqueryBuilderListenerImpl used on opensource projects

Example 1 with SubqueryBuilderListenerImpl

use of com.blazebit.persistence.impl.SubqueryBuilderListenerImpl in project blaze-persistence by Blazebit.

the class SizeTransformationVisitor method generateSubquery.

private SubqueryExpression generateSubquery(PathExpression sizeArg) {
    JoinNode sizeArgJoin = (JoinNode) sizeArg.getBaseNode();
    final Type<?> nodeType = sizeArgJoin.getNodeType();
    if (!(nodeType instanceof EntityType<?>)) {
        throw new IllegalArgumentException("Size on a collection owned by a non-entity type is not supported yet: " + sizeArg);
    }
    final EntityType<?> startType = (EntityType<?>) nodeType;
    Subquery countSubquery = (Subquery) subqueryInitFactory.createSubqueryInitiator(null, new SubqueryBuilderListenerImpl<>(), false, getClause()).from(sizeArg.getPathReference().toString()).select("COUNT(*)");
    for (SingularAttribute<?, ?> idAttribute : JpaMetamodelUtils.getIdAttributes(startType)) {
        String groupByExprString = sizeArgJoin.getAlias() + "." + idAttribute.getName();
        ResolvedExpression groupByExpr = new ResolvedExpression(groupByExprString, null);
        Set<ClauseType> clauseTypes = subqueryGroupBys.get(groupByExpr);
        if (clauseTypes == null) {
            List<PathElementExpression> pathElementExpressions = new ArrayList<>(2);
            pathElementExpressions.add(new PropertyExpression(sizeArgJoin.getAlias()));
            pathElementExpressions.add(new PropertyExpression(idAttribute.getName()));
            PathExpression pathExpression = new PathExpression(pathElementExpressions);
            pathExpression.setPathReference(new SimplePathReference(sizeArgJoin, idAttribute.getName(), metamodel.type(JpaMetamodelUtils.resolveFieldClass(startType.getJavaType(), idAttribute))));
            groupByExpr = new ResolvedExpression(groupByExprString, pathExpression);
            subqueryGroupBys.put(groupByExpr, EnumSet.of(clause));
        } else {
            clauseTypes.add(clause);
        }
    }
    return new SubqueryExpression(countSubquery);
}