Examples with ExistsParseNode org.apache.phoenix.parse.ExistsParseNode used on opensource projects

Example 1 with ExistsParseNode

use of org.apache.phoenix.parse.ExistsParseNode in project phoenix by apache.

the class SubqueryRewriter method visitLeave.

@Override
public ParseNode visitLeave(ExistsParseNode node, List<ParseNode> l) throws SQLException {
    boolean isTopNode = topNode == node;
    if (isTopNode) {
        topNode = null;
    }
    SubqueryParseNode subqueryNode = (SubqueryParseNode) l.get(0);
    SelectStatement subquery = fixSubqueryStatement(subqueryNode.getSelectNode());
    String rhsTableAlias = ParseNodeFactory.createTempAlias();
    JoinConditionExtractor conditionExtractor = new JoinConditionExtractor(subquery, resolver, connection, rhsTableAlias);
    ParseNode where = subquery.getWhere() == null ? null : subquery.getWhere().accept(conditionExtractor);
    if (where == subquery.getWhere()) {
        // non-correlated EXISTS subquery, add LIMIT 1
        subquery = NODE_FACTORY.select(subquery, NODE_FACTORY.limit(NODE_FACTORY.literal(1)));
        subqueryNode = NODE_FACTORY.subquery(subquery, false);
        node = NODE_FACTORY.exists(subqueryNode, node.isNegate());
        return super.visitLeave(node, Collections.<ParseNode>singletonList(subqueryNode));
    }
    List<AliasedNode> additionalSelectNodes = conditionExtractor.getAdditionalSelectNodes();
    List<AliasedNode> selectNodes = Lists.newArrayListWithExpectedSize(additionalSelectNodes.size() + 1);
    selectNodes.add(NODE_FACTORY.aliasedNode(ParseNodeFactory.createTempAlias(), LiteralParseNode.ONE));
    selectNodes.addAll(additionalSelectNodes);
    subquery = NODE_FACTORY.select(subquery, true, selectNodes, where);
    ParseNode onNode = conditionExtractor.getJoinCondition();
    TableNode rhsTable = NODE_FACTORY.derivedTable(rhsTableAlias, subquery);
    JoinType joinType = isTopNode ? (node.isNegate() ? JoinType.Anti : JoinType.Semi) : JoinType.Left;
    ParseNode ret = isTopNode ? null : NODE_FACTORY.isNull(NODE_FACTORY.column(NODE_FACTORY.table(null, rhsTableAlias), selectNodes.get(0).getAlias(), null), !node.isNegate());
    tableNode = NODE_FACTORY.join(joinType, tableNode, rhsTable, onNode, false);
    return ret;
}