de.greenrobot.dao.query.DeleteQuery Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of greendao Show documentation
Forked library from the original greendao from greenrobot
The newest version!
/*
 * Copyright (C) 2011-2015 Markus Junginger, greenrobot (http://greenrobot.de)
 *
 * 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 de.greenrobot.dao.query;

import de.greenrobot.dao.AbstractDao;
import de.greenrobot.dao.database.Database;

/**
 * A repeatable query for deleting entities.

 * New API note: this is more likely to change.
 *
 * @param  The entity class the query will delete from.
 * @author Markus
 */
public class DeleteQuery extends AbstractQuery {
    private final static class QueryData extends AbstractQueryData> {

        private QueryData(AbstractDao dao, String sql, String[] initialValues) {
            super(dao, sql, initialValues);
        }

        @Override
        protected DeleteQuery createQuery() {
            return new DeleteQuery(this, dao, sql, initialValues.clone());
        }
    }

    static  DeleteQuery create(AbstractDao dao, String sql, Object[] initialValues) {
        QueryData queryData = new QueryData(dao, sql, toStringArray(initialValues));
        return queryData.forCurrentThread();
    }

    private final QueryData queryData;

    private DeleteQuery(QueryData queryData, AbstractDao dao, String sql, String[] initialValues) {
        super(dao, sql, initialValues);
        this.queryData = queryData;
    }

    public DeleteQuery forCurrentThread() {
        return queryData.forCurrentThread(this);
    }

    /**
     * Deletes all matching entities without detaching them from the identity scope (aka session/cache). Note that this
     * method may lead to stale entity objects in the session cache. Stale entities may be returned when loaded by
     * their
     * primary key, but not using queries.
     */
    public void executeDeleteWithoutDetachingEntities() {
        checkThread();
        Database db = dao.getDatabase();
        if (db.isDbLockedByCurrentThread()) {
            dao.getDatabase().execSQL(sql, parameters);
        } else {
            // Do TX to acquire a connection before locking this to avoid deadlocks
            // Locking order as described in AbstractDao
            db.beginTransaction();
            try {
                dao.getDatabase().execSQL(sql, parameters);
                db.setTransactionSuccessful();
            } finally {
                db.endTransaction();
            }
        }
    }

}