TableFromBuilderImpl.java

/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.apache.metamodel.query.builder;

import java.util.List;

import org.apache.metamodel.DataContext;
import org.apache.metamodel.query.FromItem;
import org.apache.metamodel.query.JoinType;
import org.apache.metamodel.query.Query;
import org.apache.metamodel.schema.Table;

final class TableFromBuilderImpl extends SatisfiedFromBuilderCallback implements TableFromBuilder {

    private FromItem fromItem;

    public TableFromBuilderImpl(Table table, Query query, DataContext dataContext) {
        super(query, dataContext);

        fromItem = new FromItem(table);
        query.from(fromItem);
    }

    @Override
    public JoinFromBuilder innerJoin(String tableName) {
        return innerJoin(findTable(tableName));
    }

    @Override
    public JoinFromBuilder innerJoin(Table table) {
        if (table == null) {
            throw new IllegalArgumentException("table cannot be null");
        }
        return new JoinFromBuilderImpl(getQuery(), fromItem, table, JoinType.INNER, getDataContext());
    }

    @Override
    public JoinFromBuilder leftJoin(String tableName) {
        return leftJoin(findTable(tableName));
    }

    @Override
    public JoinFromBuilder leftJoin(Table table) {
        if (table == null) {
            throw new IllegalArgumentException("table cannot be null");
        }
        return new JoinFromBuilderImpl(getQuery(), fromItem, table, JoinType.LEFT, getDataContext());
    }

    @Override
    public JoinFromBuilder rightJoin(String tableName) {
        return rightJoin(findTable(tableName));
    }

    @Override
    public JoinFromBuilder rightJoin(Table table) {
        if (table == null) {
            throw new IllegalArgumentException("table cannot be null");
        }
        return new JoinFromBuilderImpl(getQuery(), fromItem, table, JoinType.RIGHT, getDataContext());
    }

    @Override
    public TableFromBuilder as(String alias) {
        if (alias == null) {
            throw new IllegalArgumentException("alias cannot be null");
        }
        fromItem.setAlias(alias);
        return this;
    }

    @Override
    protected void decorateIdentity(List<Object> identifiers) {
        super.decorateIdentity(identifiers);
        identifiers.add(fromItem);
    }

    private Table findTable(String tableName) {
        if (tableName == null) {
            throw new IllegalArgumentException("tableName cannot be null");
        }
        Table table = getDataContext().getTableByQualifiedLabel(tableName);
        if (table == null) {
            throw new IllegalArgumentException("No such table: " + tableName);
        }
        return table;
    }
}