hive中 regexp_replace的用法，替换特殊字符问题

Posted 2021-01-18 woshimrf

数据仓库中有的字段不合格，有特殊字符，比如换行符。

poi_name

19013

12013

怎么把换行符替换掉呢？

https://cwiki.apache.org/confluence/display/Hive/LanguageManual+UDF#LanguageManualUDF-StringOperators

regexp_replace(string INITIAL_STRING, string PATTERN, string REPLACEMENT)

Returns the string resulting from replacing all substrings in INITIAL_STRING that match the java regular expression syntax defined in PATTERN with instances of REPLACEMENT. For example, regexp_replace("foobar", "oo|ar", "") returns ‘fb.‘ Note that some care is necessary in using predefined character classes: using ‘s‘ as the second argument will match the letter s; ‘s‘ is necessary to match whitespace, etc.

官网说用两个反斜杠代替一个，即一个反斜杠用来转义。

实践了一下，不行，得4个

````
select regexp_replace(poi_name,‘\n‘,‘‘)

poi_name
19013
12013
```