protected List query2Select()

in hugegraph-mysql/src/main/java/org/apache/hugegraph/backend/store/mysql/MysqlTable.java [489:548]
46 lines of code
12 McCabe index (conditional complexity)

    protected List<StringBuilder> query2Select(String table, Query query) {
        // Build query
        StringBuilder select = new StringBuilder(64);
        select.append("SELECT ");

        // Set aggregate
        Aggregate aggregate = query.aggregate();
        if (aggregate != null) {
            select.append(aggregate.toString());
        } else {
            select.append("*");
        }

        // Set table
        select.append(" FROM ").append(table);

        // Is query by id?
        List<StringBuilder> ids = this.queryId2Select(query, select);

        List<StringBuilder> selections;

        if (query.conditionsSize() == 0) {
            // Query only by id
            LOG.debug("Query only by id(s): {}", ids);
            selections = ids;
        } else {
            ConditionQuery condQuery = (ConditionQuery) query;
            if (condQuery.containsScanRelation()) {
                assert ids.size() == 1;
                return ImmutableList.of(queryByRange(condQuery, ids.get(0)));
            }

            selections = new ArrayList<>(ids.size());
            for (StringBuilder selection : ids) {
                // Query by condition
                selections.addAll(this.queryCondition2Select(query, selection));
            }
            LOG.debug("Query by conditions: {}", selections);
        }
        // Set page, order-by and limit
        for (StringBuilder selection : selections) {
            boolean hasOrder = !query.orders().isEmpty();
            if (hasOrder) {
                this.wrapOrderBy(selection, query);
            }
            if (query.paging()) {
                this.wrapPage(selection, query, false);
                wrapLimit(selection, query);
            } else {
                if (aggregate == null && !hasOrder) {
                    select.append(this.orderByKeys());
                }
                if (!query.noLimit() || query.offset() > 0L) {
                    this.wrapOffset(selection, query);
                }
            }
        }

        return selections;
    }