igor-suhorukov commented on code in PR #14081: URL: https://github.com/apache/arrow/pull/14081#discussion_r967250982
########## java/adapter/jdbc/src/test/java/org/apache/arrow/adapter/jdbc/JdbcToArrowCommentMetadataTest.java: ########## @@ -0,0 +1,168 @@ +/* + * 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 static org.assertj.core.api.Assertions.assertThat; + +import java.nio.charset.StandardCharsets; +import java.nio.file.Files; +import java.nio.file.Paths; +import java.sql.Connection; +import java.sql.DatabaseMetaData; +import java.sql.DriverManager; +import java.sql.ResultSet; +import java.sql.ResultSetMetaData; +import java.sql.SQLException; +import java.sql.Statement; +import java.util.HashMap; +import java.util.HashSet; +import java.util.Map; +import java.util.Objects; +import java.util.Set; + +import org.apache.arrow.memory.RootAllocator; +import org.apache.arrow.vector.types.pojo.Schema; +import org.apache.arrow.vector.util.ObjectMapperFactory; +import org.junit.After; +import org.junit.Before; +import org.junit.Test; + +import com.fasterxml.jackson.databind.ObjectWriter; + +public class JdbcToArrowCommentMetadataTest { + + private final ObjectWriter schemaSerializer = ObjectMapperFactory.newObjectMapper().writerWithDefaultPrettyPrinter(); + private Connection conn = null; + + /** + * This method creates Connection object and DB table and also populate data into table for test. + * + * @throws SQLException on error + * @throws ClassNotFoundException on error + */ + @Before + public void setUp() throws SQLException, ClassNotFoundException { + String url = "jdbc:h2:mem:JdbcToArrowTest?characterEncoding=UTF-8;INIT=runscript from 'classpath:/h2/comment.sql'"; + String driver = "org.h2.Driver"; + Class.forName(driver); + conn = DriverManager.getConnection(url); + } + + @After + public void tearDown() throws SQLException { + if (conn != null) { + conn.close(); + conn = null; + } + } + + @Test + public void schemaComment() throws Exception { + boolean includeMetadata = false; + String schemaJson = schemaSerializer.writeValueAsString(getSchemaWithCommentFromQuery(includeMetadata)); + String expectedSchema = getExpectedSchema("/h2/expectedSchemaWithComments.json"); + assertThat(schemaJson).isEqualTo(expectedSchema); + } + + @Test + public void schemaCommentWithDatabaseMetadata() throws Exception { + boolean includeMetadata = true; + String schemaJson = schemaSerializer.writeValueAsString(getSchemaWithCommentFromQuery(includeMetadata)); + String expectedSchema = getExpectedSchema("/h2/expectedSchemaWithCommentsAndJdbcMeta.json"); + assertThat(schemaJson).isEqualTo(expectedSchema); + } + + private Schema getSchemaWithCommentFromQuery(boolean includeMetadata) throws SQLException { + DatabaseMetaData metaData = conn.getMetaData(); + try (Statement statement = conn.createStatement()) { + try (ResultSet resultSet = statement.executeQuery("select * from table1")) { + ResultSetMetaData resultSetMetaData = resultSet.getMetaData(); + Map<Integer, String> columnCommentByColumnIndex = getColumnComments(metaData, resultSetMetaData); + + String tableName = getTableNameFromResultSetMetaData(resultSetMetaData); + String tableComment = getTableComment(metaData, tableName); + JdbcToArrowConfig config = new JdbcToArrowConfigBuilder() + .setAllocator(new RootAllocator()).setSchemaComment(tableComment) + .setColumnCommentByColumnIndex(columnCommentByColumnIndex).setIncludeMetadata(includeMetadata).build(); + return JdbcToArrowUtils.jdbcToArrowSchema(resultSetMetaData, config); Review Comment: Good idea, @lidavidm! Do you mean change new JdbcToArrowConfig fields to : private final Map<String,String> schemaMetadata; private final Map<Integer, Map<String,String>> columnMetadataByColumnIndex; ? To allow user provide any additional metadata for schema/column level? For me such approach is super rational - it allows propagate additional metadata for example SRID related to geometry /Spatial Reference Systems It also allow to remove hard coded name String COMMENT = "comment" from source and move naming responsibility to developer side -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
