CODEWITHSUNDEEP
regexsnowflake-cloud-data-platformsnowsql
marjun
marjun

Reputation: 726

Invalid regular expression error in snowflake

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: +

Upvotes: 2

Views: 3759

Answers (2)

Hans Henrik Eriksen
Hans Henrik Eriksen

Reputation: 2850

You need to use double escapes with Snowflake. If you just select your regexp string you will get:

SELECT '/(_((\-|\+)?[0-9]+(\.[0-9]+)?).)/';
=>   /(_((-|+)?[0-9]+(.[0-9]+)?).)/

which is exactly what the regexp function will get as an input argument as well.
With double escapes you get:

SELECT '/(_((\\-|\\+)?[0-9]+(\\.[0-9]+)?).)/';
=>   /(_((\-|\+)?[0-9]+(\.[0-9]+)?).)/

which is what I believe you want.

The error you get is from the regexp (-|+); the + operator needs a real argument...

Upvotes: 0

Wiktor Stribiżew
Wiktor Stribiżew

Reputation: 626689

Use

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

This is the regex demo

The pattern matches _, then captures one or more digits in Group 1 and then matches .. Since the group_num argument is 1, the return value is Group 1 value.

Upvotes: 3

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