DESCRIBE EXTERNAL TABLE¶
描述外部表中的 VALUE 列和虚拟列。
DESCRIBE 可以缩写为 DESC。
语法¶
DESC[RIBE] [ EXTERNAL ] TABLE <name> [ TYPE = { COLUMNS | STAGE } ]
参数¶
name指定要描述的外部表的标识符。如果标识符包含空格或特殊字符，则整个字符串必须放在双引号内。放在双引号内的标识符也区分大小写。
使用说明¶
To post-process the output of this command, you can use the pipe operator (
->>) or the RESULT_SCAN function. Both constructs treat the output as a result set that you can query.The output column names for this command are generated in lowercase. If you consume a result set from this command with the pipe operator or the RESULT_SCAN function, use double-quoted identifiers for the column names in the query to ensure that they match the column names in the output that was scanned. For example, if the name of an output column is
type, then specify"type"for the identifier.
示例¶
创建一个示例外部表：
CREATE EXTERNAL TABLE emp ( ... );
描述表中的列：
DESC EXTERNAL TABLE emp;