org.apache.phoenix.pig.util.SqlQueryToColumnInfoFunction Maven / Gradle / Ivy
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* 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
*
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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.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.util.ColumnInfo;
import com.google.common.base.Function;
import com.google.common.base.Preconditions;
import com.google.common.collect.Lists;
public final class SqlQueryToColumnInfoFunction implements Function> {
private static final Log LOG = LogFactory.getLog(SqlQueryToColumnInfoFunction.class);
private final Configuration configuration;
public SqlQueryToColumnInfoFunction(final Configuration configuration) {
this.configuration = configuration;
}
@Override
public List apply(String sqlQuery) {
Preconditions.checkNotNull(sqlQuery);
Connection connection = null;
List columnInfos = null;
try {
connection = ConnectionUtil.getInputConnection(this.configuration);
final Statement statement = connection.createStatement();
final PhoenixStatement pstmt = statement.unwrap(PhoenixStatement.class);
final QueryPlan queryPlan = pstmt.compileQuery(sqlQuery);
final List projectedColumns = queryPlan.getProjector().getColumnProjectors();
columnInfos = Lists.newArrayListWithCapacity(projectedColumns.size());
columnInfos = Lists.transform(projectedColumns, new Function() {
@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));
throw new RuntimeException(e);
} finally {
if(connection != null) {
try {
connection.close();
} catch(SQLException sqle) {
LOG.error("Error closing connection!!");
throw new RuntimeException(sqle);
}
}
}
return columnInfos;
}
}