regex - Invalid regular expression error in snowflake

Question

I'm trying to extract date (20200222) from filename while copyinto command in snowflake.

File Name

s3://hadoop/2020002/dbo.DOSSIER_TRANSPORT_20200222.csv.gz

snowflake query

SELECT regexp_substr(metadata$filename, '/(_((\-|\+)?[0-9]+(\.[0-9]+)?).)/' as data FROM '@PRD.OPE_STG
                                                _CMD.SPX_PRD_CMD/' (file_format => 'OTS_TEST.OPA_STG_BENE.OTD_FORMAT', pattern => '.*dbo.DOSSIER_TRANSPORT.*') ;

I tried this regex but its not supporting in snowflake. Getting below error

100048 (2201B): Invalid regular expression: '/(_((-|+)?[0-9]+(.[0-9]+)?).)/', no argument for repetition operator: +

标签： regexsnowflake-cloud-data-platformsnowsql

Answer 1

利用

REGEXP_SUBSTR(metadata$filename, '_([0-9]+)[.]', 1, 1, 'c', 1)

这是正则表达式演示

模式匹配_，然后捕获组 1 中的一个或多个数字，然后匹配.。由于group_num参数为1，因此返回值为 Group 1 值。