com.blazebit.persistence.impl.query.CollectionDeleteModificationQuerySpecification Maven / Gradle / Ivy

/*
 * Copyright 2014 - 2020 Blazebit.
 *
 * 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 com.blazebit.persistence.impl.query;

import com.blazebit.persistence.impl.AbstractCommonQueryBuilder;
import com.blazebit.persistence.impl.util.SqlUtils;
import com.blazebit.persistence.spi.DbmsModificationState;

import javax.persistence.Parameter;
import javax.persistence.Query;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import java.util.Set;

/**
 *
 * @author Christian Beikov
 * @since 1.2.0
 */
public class CollectionDeleteModificationQuerySpecification extends ModificationQuerySpecification {

    private final Query deleteExampleQuery;
    private final String deleteSql;
    private final Map columnExpressionRemappings;

    public CollectionDeleteModificationQuerySpecification(AbstractCommonQueryBuilder commonQueryBuilder, Query baseQuery, Query exampleQuery, Set> parameters, Set parameterListNames, boolean recursive, List ctes, boolean shouldRenderCteNodes,
                                                          boolean isEmbedded, String[] returningColumns, Map includedModificationStates, Map returningAttributeBindingMap, Query deleteExampleQuery, String deleteSql, Map columnExpressionRemappings) {
        super(commonQueryBuilder, baseQuery, exampleQuery, parameters, parameterListNames, recursive, ctes, shouldRenderCteNodes, isEmbedded, returningColumns, includedModificationStates, returningAttributeBindingMap);
        this.deleteExampleQuery = deleteExampleQuery;
        this.deleteSql = deleteSql;
        this.columnExpressionRemappings = columnExpressionRemappings;
    }

    @Override
    protected void initialize() {
        List participatingQueries = new ArrayList<>();

        for (Map.Entry> entry : listParameters.entrySet()) {
            baseQuery.setParameter(entry.getKey(), entry.getValue());
        }

        StringBuilder sqlSb = new StringBuilder(extendedQuerySupport.getSql(em, baseQuery));

        // Replace the "select ... from ..." part of the base query by the "delete from collectionTable" part
        int whereIndex = SqlUtils.indexOfWhere(sqlSb);
        if (whereIndex == -1) {
            sqlSb.setLength(0);
            sqlSb.append(deleteSql);
        } else {
            sqlSb.replace(0, whereIndex, deleteSql);
        }

        remapColumnExpressions(sqlSb, columnExpressionRemappings);

        StringBuilder withClause = applyCtes(sqlSb, baseQuery, participatingQueries);
        // NOTE: CTEs will only be added, if this is a subquery
        Map addedCtes = applyExtendedSql(sqlSb, false, isEmbedded, withClause, returningColumns, includedModificationStates);
        participatingQueries.add(baseQuery);

        // Some dbms like DB2 will need to wrap modification queries in select queries when using CTEs
        boolean hasCtes = withClause != null && withClause.length() != 0 || addedCtes != null && !addedCtes.isEmpty();
        if (hasCtes && returningAttributeBindingMap.isEmpty() && !dbmsDialect.usesExecuteUpdateWhenWithClauseInModificationQuery()) {
            query = exampleQuery;
        } else {
            query = deleteExampleQuery;
        }

        this.sql = sqlSb.toString();
        this.participatingQueries = participatingQueries;
        this.addedCtes = addedCtes;
        this.dirty = false;
    }
}