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-encryption Show documentation
greenDAO is a light and fast ORM for Android
There is a newer version: 3.0.0-beta3
/*
 * 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();
            }
        }
    }

}