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_r372707601
########## 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 = { + val ns = ident.namespace() + checkNamespace(ns) + withConnection { conn => + val md = conn.getMetaData + val schemaPattern = if (ns.length == 1) ns.head else null + val rs = md.getTables(null, schemaPattern, ident.name(), Array("TABLE")); + rs.next() + } + } + + override def renameTable(oldIdent: Identifier, newIdent: Identifier): Unit = { + // TODO: support this by adding more APIs to `JdbcDialect` which can generate the SQL statement + // to rename a table. + throw new UnsupportedOperationException("rename table") + } + + override def alterTable(ident: Identifier, changes: TableChange*): Table = { + // TODO: support this by adding more APIs to `JdbcDialect` which can generate the SQL statement + // to alter a table. + throw new UnsupportedOperationException("alter table") + } + + override def dropTable(ident: Identifier): Boolean = { + checkNamespace(ident.namespace()) + try { + withConnection { conn => + val statement = conn.createStatement + statement.setQueryTimeout(options.queryTimeout) + statement.executeUpdate(s"DROP TABLE ${getTableName(ident)}") + true + } + } catch { + case _: SQLException => false + } + } + + override def loadTable(ident: Identifier): Table = { + checkNamespace(ident.namespace()) + val optionsWithTableName = createOptionsWithTableName(ident) + try { + val schema = JDBCRDD.resolveTable(optionsWithTableName) + JDBCTable(ident, schema, optionsWithTableName) + } catch { + case _: SQLException => throw new NoSuchTableException(ident) + } + } + + override def createTable( + ident: Identifier, + schema: StructType, + partitions: Array[Transform], + properties: util.Map[String, String]): Table = { + checkNamespace(ident.namespace()) + if (partitions.nonEmpty) { + throw new UnsupportedOperationException("Cannot create JDBC table with partition") + } + // TODO: we can support this, but we need to add an API to `JdbcDialect` to generate the SQL + // statement to specify table options. + if (!properties.isEmpty) { + logWarning("Cannot create JDBC table with properties, these properties will be " + + "ignored: " + properties.asScala.map { case (k, v) => s"$k=$v" }.mkString("[", ", ", "]")) Review comment: @dongjoon-hyun good point, +1 ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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