# PostgreSQLQuerying.java

    /*
     * Copyright (c) 2010, Stanislav Muhametsin. All Rights Reserved.
     * Copyright (c) 2012, Paul Merlin. All Rights Reserved.
     *
     * 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 org.qi4j.index.sql.support.postgresql;

    import java.util.List;
    import java.util.Map;
    import org.qi4j.api.composite.Composite;
    import org.qi4j.api.query.grammar.OrderBy;
    import org.qi4j.functional.Specification;
    import org.qi4j.index.sql.support.skeletons.AbstractSQLQuerying;
    import org.sql.generation.api.grammar.builders.query.QuerySpecificationBuilder;
    import org.sql.generation.api.grammar.query.QueryExpression;
    import org.sql.generation.api.vendor.SQLVendor;

    public class PostgreSQLQuerying
            extends AbstractSQLQuerying
    {

        @Override
        protected QueryExpression finalizeQuery(
                SQLVendor sqlVendor, QuerySpecificationBuilder specBuilder,
                Class<?> resultType,
                Specification<Composite> whereClause,
                OrderBy[] orderBySegments,
                Integer firstResult,
                Integer maxResults,
                Map<String, Object> variables,
                List<Object> values,
                List<Integer> valueSQLTypes,
                Boolean countOnly )
        {
            Boolean needOffset = firstResult != null && firstResult > 0;
            Boolean needLimit = maxResults != null && maxResults > 0;

            if ( needOffset ) {
                specBuilder.offset( firstResult );
            }
            if ( needLimit ) {
                specBuilder.limit( maxResults );
            }

            return sqlVendor.getQueryFactory().createQuery( specBuilder.createExpression() );
        }

    }