gengliangwang commented on a change in pull request #27345: [SPARK-30624][SQL] JDBC v2 with catalog functionalities URL: https://github.com/apache/spark/pull/27345#discussion_r372698348
########## File path: sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/v2/jdbc/JDBCTableCatalog.scala ########## @@ -0,0 +1,167 @@ +/* + * 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.spark.sql.execution.datasources.v2.jdbc + +import java.sql.{Connection, SQLException} +import java.util + +import scala.collection.JavaConverters._ +import scala.collection.mutable.ArrayBuffer + +import org.apache.spark.internal.Logging +import org.apache.spark.sql.catalyst.analysis.{NoSuchNamespaceException, NoSuchTableException} +import org.apache.spark.sql.connector.catalog.{Identifier, Table, TableCatalog, TableChange} +import org.apache.spark.sql.connector.expressions.Transform +import org.apache.spark.sql.execution.datasources.jdbc.{JDBCOptions, JdbcOptionsInWrite, JDBCRDD, JdbcUtils} +import org.apache.spark.sql.internal.SQLConf +import org.apache.spark.sql.jdbc.{JdbcDialect, JdbcDialects} +import org.apache.spark.sql.types.StructType +import org.apache.spark.sql.util.CaseInsensitiveStringMap + +class JDBCTableCatalog extends TableCatalog with Logging { + + private var _name: String = _ + private var options: JDBCOptions = _ + private var dialect: JdbcDialect = _ + + override def initialize(name: String, options: CaseInsensitiveStringMap): Unit = { + _name = name + val map = options.asCaseSensitiveMap().asScala.toMap + // The `JDBCOptions` checks the existence of the table option. This is required by JDBC v1, but + // JDBC V2 only knows the table option when loading a table. Here we put a table option with a + // fake value, so that it can pass the check of `JDBCOptions`. + this.options = new JDBCOptions(map + (JDBCOptions.JDBC_TABLE_NAME -> "__invalid")) + this.dialect = JdbcDialects.get(this.options.url) + } + + override def name(): String = { + _name + } + + private def withConnection[T](f: Connection => T): T = { + val conn = JdbcUtils.createConnectionFactory(options)() + try { + f(conn) + } finally { + conn.close() + } + } + + private def checkNamespace(namespace: Array[String]): Unit = { + // In JDBC there is no nested database/schema + if (namespace.length > 1) { + throw new NoSuchNamespaceException(namespace) + } + } + + private def getTableName(ident: Identifier): String = { + (ident.namespace() :+ ident.name()).map(dialect.quoteIdentifier).mkString(".") + } + + private def createOptionsWithTableName(ident: Identifier): JDBCOptions = { + new JDBCOptions(options.parameters + (JDBCOptions.JDBC_TABLE_NAME -> getTableName(ident))) + } + + override def listTables(namespace: Array[String]): Array[Identifier] = { + checkNamespace(namespace) + withConnection { conn => + val md = conn.getMetaData + val schemaPattern = if (namespace.length == 1) namespace.head else null + val rs = md.getTables(null, schemaPattern, "%", Array("TABLE")); + val tables = ArrayBuffer.empty[Identifier] + while (rs.next()) { + tables += Identifier.of(namespace, rs.getString("TABLE_NAME")) + } + tables.toArray + } + } + + override def tableExists(ident: Identifier): Boolean = { Review comment: The implementation of `tableExists` is different with `JdbcUtils.tableExists`. Should we unify them? ---------------------------------------------------------------- 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. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
