viirya commented on a change in pull request #26182: [SPARK-29523][SQL] SHOW COLUMNS should do multi-catalog resolution. URL: https://github.com/apache/spark/pull/26182#discussion_r340289667
########## File path: sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/parser/AstBuilder.scala ########## @@ -2912,6 +2912,32 @@ class AstBuilder(conf: SQLConf) extends SqlBaseBaseVisitor[AnyRef] with Logging RefreshTableStatement(visitMultipartIdentifier(ctx.multipartIdentifier())) } + /** + * A command for users to list the column names for a table. + * This function creates a [[ShowColumnsStatement]] logical plan. + * + * The syntax of using this command in SQL is: + * {{{ + * SHOW COLUMNS (FROM | IN) tableName=multipartIdentifier + * ((FROM | IN) namespace=multipartIdentifier)? + * }}} + */ + override def visitShowColumns(ctx: ShowColumnsContext): LogicalPlan = withOrigin(ctx) { + import org.apache.spark.sql.connector.catalog.CatalogV2Implicits._ + + val table = visitMultipartIdentifier(ctx.table) + val namespace = Option(ctx.namespace).map(visitMultipartIdentifier) + if (namespace.isDefined && namespace.get.length > 1) { + throw new ParseException( + s"Namespace name should have only one part if specified: ${namespace.get.quoted}", ctx) + } + if (table.length > 2) { + throw new ParseException( + s"Table name should have at most two parts: ${table.quoted}", ctx) + } Review comment: Should we move the checks to Analyzer? Let ResolveSessionCatalog do the check? ---------------------------------------------------------------- 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: us...@infra.apache.org With regards, Apache Git Services --------------------------------------------------------------------- To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For additional commands, e-mail: reviews-h...@spark.apache.org