Github user hvanhovell commented on a diff in the pull request: https://github.com/apache/spark/pull/12133#discussion_r58308046 --- Diff: sql/core/src/main/scala/org/apache/spark/sql/execution/command/commands.scala --- @@ -374,6 +374,52 @@ case class ShowDatabasesCommand(databasePattern: Option[String]) extends Runnabl } /** + * A command for users to list the properties for a table. + * If propertyKey is specified, the value for the propertyKey + * is returned. If propertyKey is not specified, all the keys + * and their corresponding values are returned. + * The syntax of using this command in SQL is: + * {{{ + * SHOW TBLPROPERTIES table_name[('propertyKey')]; + * }}} + */ +case class ShowTablePropertiesCommand( + table: TableIdentifier, + propertyKey: Option[String]) extends RunnableCommand { + + override val output: Seq[Attribute] = { + val withKeySchema: Seq[Attribute] = { + AttributeReference("value", StringType, nullable = false)() :: Nil + } + val noKeySchema: Seq[Attribute] = { + AttributeReference("key", StringType, nullable = false)() :: + AttributeReference("value", StringType, nullable = false)() :: Nil + } + propertyKey.map(p => withKeySchema).getOrElse(noKeySchema) + } + + override def run(sqlContext: SQLContext): Seq[Row] = { + val catalog = sqlContext.sessionState.catalog + + if (catalog.isTemporaryTable(table)) { + throw new AnalysisException("This operation is unsupported for temporary tables") + } + val catalogTable = sqlContext.sessionState.catalog.getTable(table) + + propertyKey match { + case Some(p) => + val errorStr = s"Table ${catalogTable.qualifiedName} does not have property: $p" + val propValue = catalogTable + .properties + .getOrElse(p, throw new AnalysisException(errorStr)) --- End diff -- There is not a syntactic/semantic/logical problem here. Lets do what you suggest, and return a row containing a property not found message.
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