jongo.sql.dialect.DerbyDialect.java Source code

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Here is the source code for jongo.sql.dialect.DerbyDialect.java

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/**
 * Copyright (C) 2011, 2012 Alejandro Ayuso
 *
 * This file is part of Jongo.
 * Jongo is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * any later version.
 * 
 * Jongo is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with Jongo.  If not, see <http://www.gnu.org/licenses/>.
 */
package jongo.sql.dialect;

import jongo.sql.Select;

import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Dialect for Apache Derby.
 */
public class DerbyDialect extends SQLDialect {

    private static final Logger l = LoggerFactory.getLogger(DerbyDialect.class);

    @Override
    public String toStatementString(final Select select) {
        final StringBuilder b = new StringBuilder("SELECT ");
        if (select.getLimitParam() == null) {
            return super.toStatementString(select);
        } else {
            b.append("* FROM ( SELECT ROW_NUMBER() OVER () AS ROW_NUM, ");

            if (select.isAllColumns()) {
                b.append("t.*");
            } else {
                String cols = StringUtils.join(select.getColumns(), ",");
                b.append("t.").append(cols);
            }

            b.append(" FROM ").append(select.getTable().toString()).append(" t");

            if (!select.isAllRecords()) {
                appendWhereClause(b, select);
            }

            b.append(") AS tmp WHERE ROW_NUM BETWEEN ").append(select.getLimitParam().getStart());
            b.append(" AND ").append(select.getLimitParam().getLimit());

            b.append(" ORDER BY tmp.");
            if (select.getOrderParam() == null) {
                b.append(select.getTable().getPrimaryKey());
            } else {
                b.append(select.getOrderParam().getColumn()).append(" ")
                        .append(select.getOrderParam().getDirection());
            }
        }
        l.debug(b.toString());
        return b.toString();
    }

    @Override
    public String listOfTablesStatement() {
        return "SELECT * FROM SYS.SYSTABLES WHERE tabletype = 'T'";
    }

}