org.apache.arrow.adapter.jdbc.JdbcToArrow Maven / Gradle / Ivy
/*
* 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.arrow.adapter.jdbc;
import java.io.IOException;
import java.sql.ResultSet;
import java.sql.SQLException;
import org.apache.arrow.memory.BufferAllocator;
import org.apache.arrow.util.Preconditions;
/**
* Utility class to convert JDBC objects to columnar Arrow format objects.
*
* This utility uses following data mapping to map JDBC/SQL datatype to Arrow data types.
*
*
CHAR --> ArrowType.Utf8
* NCHAR --> ArrowType.Utf8
* VARCHAR --> ArrowType.Utf8
* NVARCHAR --> ArrowType.Utf8
* LONGVARCHAR --> ArrowType.Utf8
* LONGNVARCHAR --> ArrowType.Utf8
* NUMERIC --> ArrowType.Decimal(precision, scale)
* DECIMAL --> ArrowType.Decimal(precision, scale)
* BIT --> ArrowType.Bool
* TINYINT --> ArrowType.Int(8, signed)
* SMALLINT --> ArrowType.Int(16, signed)
* INTEGER --> ArrowType.Int(32, signed)
* BIGINT --> ArrowType.Int(64, signed)
* REAL --> ArrowType.FloatingPoint(FloatingPointPrecision.SINGLE)
* FLOAT --> ArrowType.FloatingPoint(FloatingPointPrecision.SINGLE)
* DOUBLE --> ArrowType.FloatingPoint(FloatingPointPrecision.DOUBLE)
* BINARY --> ArrowType.Binary
* VARBINARY --> ArrowType.Binary
* LONGVARBINARY --> ArrowType.Binary
* DATE --> ArrowType.Date(DateUnit.MILLISECOND)
* TIME --> ArrowType.Time(TimeUnit.MILLISECOND, 32)
* TIMESTAMP --> ArrowType.Timestamp(TimeUnit.MILLISECOND, timezone=null)
* CLOB --> ArrowType.Utf8
* BLOB --> ArrowType.Binary
*
* @since 0.10.0
*/
public class JdbcToArrow {
/*----------------------------------------------------------------*
| |
| Partial Convert API |
| |
*----------------------------------------------------------------*/
/**
* For the given JDBC {@link ResultSet}, fetch the data from Relational DB and convert it to Arrow objects.
* Note here uses the default targetBatchSize = 1024.
*
* @param resultSet ResultSet to use to fetch the data from underlying database
* @param allocator Memory allocator
* @return Arrow Data Objects {@link ArrowVectorIterator}
* @throws SQLException on error
*/
public static ArrowVectorIterator sqlToArrowVectorIterator(
ResultSet resultSet,
BufferAllocator allocator)
throws SQLException, IOException {
Preconditions.checkNotNull(allocator, "Memory Allocator object can not be null");
JdbcToArrowConfig config =
new JdbcToArrowConfig(allocator, JdbcToArrowUtils.getUtcCalendar());
return sqlToArrowVectorIterator(resultSet, config);
}
/**
* For the given JDBC {@link ResultSet}, fetch the data from Relational DB and convert it to Arrow objects.
* Note if not specify {@link JdbcToArrowConfig#targetBatchSize}, will use default value 1024.
* @param resultSet ResultSet to use to fetch the data from underlying database
* @param config Configuration of the conversion from JDBC to Arrow.
* @return Arrow Data Objects {@link ArrowVectorIterator}
* @throws SQLException on error
*/
public static ArrowVectorIterator sqlToArrowVectorIterator(
ResultSet resultSet,
JdbcToArrowConfig config)
throws SQLException, IOException {
Preconditions.checkNotNull(resultSet, "JDBC ResultSet object can not be null");
Preconditions.checkNotNull(config, "The configuration cannot be null");
return ArrowVectorIterator.create(resultSet, config);
}
}