annis.sqlgen.TableJoinsInFromClauseSqlGenerator.java Source code

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Here is the source code for annis.sqlgen.TableJoinsInFromClauseSqlGenerator.java

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/*
 * Copyright 2009-2011 Collaborative Research Centre SFB 632 
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package annis.sqlgen;

import static annis.sqlgen.AbstractSqlGenerator.TABSTOP;
import static annis.sqlgen.TableAccessStrategy.COMPONENT_TABLE;
import static annis.sqlgen.TableAccessStrategy.EDGE_ANNOTATION_TABLE;
import static annis.sqlgen.TableAccessStrategy.NODE_ANNOTATION_TABLE;
import static annis.sqlgen.TableAccessStrategy.NODE_TABLE;
import static annis.sqlgen.TableAccessStrategy.RANK_TABLE;
import static annis.sqlgen.TableAccessStrategy.TEXT_TABLE;

import java.util.ArrayList;
import java.util.List;

import org.apache.commons.lang3.StringUtils;

import annis.model.QueryNode;
import annis.ql.parser.QueryData;

public class TableJoinsInFromClauseSqlGenerator extends AbstractFromClauseGenerator {

    @Override
    public String fromClause(QueryData queryData, List<QueryNode> alternative, String indent) {
        List<String> tables = new ArrayList<String>();
        for (QueryNode node : alternative)
            tables.add(fromClauseForNode(node, false));
        return StringUtils.join(tables, ",\n" + indent + TABSTOP);
    }

    public String fromClauseForNode(QueryNode node, boolean leftJoin) {
        StringBuilder sb = new StringBuilder();

        // every node uses the node table
        sb.append(tableAliasDefinition(node, NODE_TABLE, 1));

        // rank table
        if (tables(node).usesRankTable() && !tables(node).isMaterialized(RANK_TABLE, NODE_TABLE)) {
            sb.append(" ");
            sb.append(joinDefinition(node, RANK_TABLE, "node_ref", NODE_TABLE, "id", false));
        }

        // component table
        if (tables(node).usesComponentTable() && !tables(node).isMaterialized(COMPONENT_TABLE, RANK_TABLE)) {
            sb.append(" ");
            sb.append(joinDefinition(node, COMPONENT_TABLE, "id", RANK_TABLE, "component_ref", false));
        }

        // node annotations
        if (tables(node).usesNodeAnnotationTable()) {
            int start = tables(node).isMaterialized(NODE_ANNOTATION_TABLE, NODE_TABLE) ? 2 : 1;
            int size = node != null ? node.getNodeAnnotations().size() : 1;
            for (int i = start; i <= size; ++i) {
                sb.append(" ");
                sb.append(joinDefinition(node, NODE_ANNOTATION_TABLE, "node_ref", NODE_TABLE, "id", i, leftJoin));
            }
        }

        // add node annotation table if it is required by the SELECT clause, but not materialized with node table
        if (!tables(node).usesNodeAnnotationTable() && node.getNodeAnnotations().size() > 0
                && !tables(node).isMaterialized(NODE_ANNOTATION_TABLE, NODE_TABLE)) {
            sb.append(" ");
            sb.append(joinDefinition(node, NODE_ANNOTATION_TABLE, "node_ref", NODE_TABLE, "id", leftJoin));
        }

        // edge annotations
        if (tables(node).usesEdgeAnnotationTable()) {
            int start = tables(node).isMaterialized(EDGE_ANNOTATION_TABLE, RANK_TABLE) ? 2 : 1;
            int size = node != null ? node.getEdgeAnnotations().size() : 1;
            for (int i = start; i <= size; ++i) {
                sb.append(" ");
                sb.append(joinDefinition(node, EDGE_ANNOTATION_TABLE, "rank_ref", RANK_TABLE, "pre", i, leftJoin));
            }
        }

        return sb.toString();
    }

    protected String joinDefinition(QueryNode node, String table, String column, String joinedTable,
            String joinedColumn) {
        return joinDefinition(node, table, column, joinedTable, joinedColumn, false);
    }

    protected String joinDefinition(QueryNode node, String table, String column, String joinedTable,
            String joinedColumn, boolean leftJoin) {
        return joinDefinition(node, table, column, joinedTable, joinedColumn, 1, leftJoin);
    }

    protected String joinDefinition(QueryNode node, String table, String column, String joinedTable,
            String joinedColumn, int count) {
        return joinDefinition(node, table, column, joinedTable, joinedColumn, count, false);
    }

    protected String joinDefinition(QueryNode node, String table, String column, String joinedTable,
            String joinedColumn, int count, boolean leftJoin) {
        StringBuffer sb = new StringBuffer();
        if (leftJoin) {
            sb.append("LEFT OUTER ");
        }
        sb.append("JOIN ");
        sb.append(tableAliasDefinition(node, table, count));
        sb.append(" ON (");
        sb.append(tables(node).aliasedColumn(table, column, count));
        sb.append(" = ");
        sb.append(tables(node).aliasedColumn(joinedTable, joinedColumn));
        sb.append(")");
        return sb.toString();
    }

}