hadoop - 将 NULL 值从 Hive 导出到 Teradata

Question

我在 Hive 中有一个表，其中某些列具有 NULL 值，我正在使用 Teradata 连接器将该表从 Hadoop 导出到 Teradata。我的问题是 NULL 值被视为字符串 NULL 而不是 NULL。如何将 NULL 值直接导出到 Teradata？请帮忙。

Answer 1

您是否在导出命令中使用了 input-null-string 参数？根据documentation :

The --input-null-string and --input-null-non-string arguments are optional. If --input-null-string is not specified, then the string "null" will be interpreted as null for string-type columns. If --input-null-non-string is not specified, then both the string "null" and the empty string will be interpreted as null for non-string columns. Note that, the empty string will be always interpreted as null for non-string columns, in addition to other string if specified by --input-null-non-string.