| /* |
| * 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.hadoop.conf.Configuration; |
| import org.apache.hadoop.hbase.util.Pair; |
| import org.apache.phoenix.compile.ColumnProjector; |
| import org.apache.phoenix.compile.QueryPlan; |
| import org.apache.phoenix.jdbc.PhoenixStatement; |
| import org.apache.phoenix.mapreduce.util.ConnectionUtil; |
| |
| import org.apache.phoenix.thirdparty.com.google.common.base.Function; |
| import org.apache.phoenix.thirdparty.com.google.common.base.Joiner; |
| import org.apache.phoenix.thirdparty.com.google.common.base.Preconditions; |
| import org.apache.phoenix.thirdparty.com.google.common.collect.Lists; |
| |
| /** |
| * |
| * A function to parse the select query passed to LOAD into a Pair of {@code <table Name, List<columns> } |
| * |
| */ |
| public class QuerySchemaParserFunction implements Function<String,Pair<String,String>> { |
| |
| private static final Log LOG = LogFactory.getLog(QuerySchemaParserFunction.class); |
| private final Configuration configuration; |
| |
| public QuerySchemaParserFunction(Configuration configuration) { |
| Preconditions.checkNotNull(configuration); |
| this.configuration = configuration; |
| } |
| |
| @Override |
| public Pair<String, String> apply(final String selectStatement) { |
| Preconditions.checkNotNull(selectStatement); |
| Preconditions.checkArgument(!selectStatement.isEmpty(), "Select Query is empty!!"); |
| Connection connection = null; |
| try { |
| connection = ConnectionUtil.getInputConnection(this.configuration); |
| final Statement statement = connection.createStatement(); |
| final PhoenixStatement pstmt = statement.unwrap(PhoenixStatement.class); |
| final QueryPlan queryPlan = pstmt.compileQuery(selectStatement); |
| isValidStatement(queryPlan); |
| final String tableName = queryPlan.getTableRef().getTable().getName().getString(); |
| final List<? extends ColumnProjector> projectedColumns = queryPlan.getProjector().getColumnProjectors(); |
| final List<String> columns = Lists.transform(projectedColumns, |
| new Function<ColumnProjector,String>() { |
| @Override |
| public String apply(ColumnProjector column) { |
| return column.getName(); |
| } |
| }); |
| final String columnsAsStr = Joiner.on(",").join(columns); |
| return new Pair<String, String>(tableName, columnsAsStr); |
| } catch (SQLException e) { |
| LOG.error(String.format(" Error [%s] parsing SELECT query [%s] ",e.getMessage(),selectStatement)); |
| throw new RuntimeException(e); |
| } finally { |
| if(connection != null) { |
| try { |
| connection.close(); |
| } catch(SQLException sqle) { |
| LOG.error(" Error closing connection "); |
| throw new RuntimeException(sqle); |
| } |
| } |
| } |
| } |
| |
| /** |
| * The method validates the statement passed to the query plan. List of conditions are |
| * <ol> |
| * <li>Is a SELECT statement</li> |
| * <li>doesn't contain ORDER BY expression</li> |
| * <li>doesn't contain LIMIT</li> |
| * <li>doesn't contain GROUP BY expression</li> |
| * <li>doesn't contain DISTINCT</li> |
| * <li>doesn't contain AGGREGATE functions</li> |
| * </ol> |
| * @param queryPlan |
| * @return |
| */ |
| private boolean isValidStatement(final QueryPlan queryPlan) { |
| if(queryPlan.getStatement().getOperation() != PhoenixStatement.Operation.QUERY) { |
| throw new IllegalArgumentException("Query passed isn't a SELECT statement"); |
| } |
| if(!queryPlan.getOrderBy().getOrderByExpressions().isEmpty() |
| || queryPlan.getLimit() != null |
| || (queryPlan.getGroupBy() != null && !queryPlan.getGroupBy().isEmpty()) |
| || queryPlan.getStatement().isDistinct() |
| || queryPlan.getStatement().isAggregate()) { |
| throw new IllegalArgumentException("SELECT statement shouldn't contain DISTINCT or ORDER BY or LIMIT or GROUP BY expressions"); |
| } |
| return true; |
| } |
| |
| } |