/*
* Copyright 2010 The Apache Software Foundation
*
* 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 maynot 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 applicablelaw 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.phoenix.pig.util;
import java.sql.Connection;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.List;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.phoenix.compile.ColumnProjector;
import org.apache.phoenix.compile.QueryPlan;
import org.apache.phoenix.jdbc.PhoenixStatement;
import org.apache.phoenix.pig.PhoenixPigConfiguration;
import org.apache.phoenix.util.ColumnInfo;
import com.google.common.base.Function;
import com.google.common.base.Preconditions;
import com.google.common.base.Throwables;
import com.google.common.collect.Lists;
public final class SqlQueryToColumnInfoFunction implements Function<String,List<ColumnInfo>> {
private static final Log LOG = LogFactory.getLog(SqlQueryToColumnInfoFunction.class);
private final PhoenixPigConfiguration phoenixConfiguration;
public SqlQueryToColumnInfoFunction(
final PhoenixPigConfiguration phoenixPigConfiguration) {
super();
this.phoenixConfiguration = phoenixPigConfiguration;
}
@Override
public List<ColumnInfo> apply(String sqlQuery) {
Preconditions.checkNotNull(sqlQuery);
Connection connection = null;
List<ColumnInfo> columnInfos = null;
try {
connection = this.phoenixConfiguration.getConnection();
final Statement statement = connection.createStatement();
final PhoenixStatement pstmt = statement.unwrap(PhoenixStatement.class);
final QueryPlan queryPlan = pstmt.compileQuery(sqlQuery);
final List<? extends ColumnProjector> projectedColumns = queryPlan.getProjector().getColumnProjectors();
columnInfos = Lists.newArrayListWithCapacity(projectedColumns.size());
columnInfos = Lists.transform(projectedColumns, new Function<ColumnProjector,ColumnInfo>() {
@Override
public ColumnInfo apply(final ColumnProjector columnProjector) {
return new ColumnInfo(columnProjector.getName(), columnProjector.getExpression().getDataType().getSqlType());
}
});
} catch (SQLException e) {
LOG.error(String.format(" Error [%s] parsing SELECT query [%s] ",e.getMessage(),sqlQuery));
Throwables.propagate(e);
} finally {
if(connection != null) {
try {
connection.close();
} catch(SQLException sqle) {
Throwables.propagate(sqle);
}
}
}
return columnInfos;
}
}