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https://issues.apache.org/jira/browse/HIVE-420?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12704565#action_12704565
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Zheng Shao commented on HIVE-420:
---------------------------------
With Java regex library we can easily support exclusion of several columns:
"^(ds|hr)?+.+$" will match all columns except ds and hr.
"^(dsa|ds)?+.+$" will match all columns except ds and dsa. Note that "dsa" has
to come before "ds" otherwise it won't work as expected - basically if there
exists s and t, and s is a prefix of t, then t has to come before s.
When the user is specifying column names, they should not need to specify "^"
and "$" and we should assume the regex matches the whole string.
Use http://www.fileformat.info/tool/regex.htm for testing the above examples.
{code}
"^(ds|hr)?+.+$"
Try these:
ds
hr
d
h
s
r
ads
dsa
ahr
hra
dsds
dshr
hrds
hrhr
abc
{code}
> Support regular expressions for column in select clause
> -------------------------------------------------------
>
> Key: HIVE-420
> URL: https://issues.apache.org/jira/browse/HIVE-420
> Project: Hadoop Hive
> Issue Type: New Feature
> Components: Query Processor
> Affects Versions: 0.2.0, 0.3.0, 0.3.1, 0.4.0
> Reporter: Prasad Chakka
> Priority: Minor
>
> support queries like `select a.[^ds] from a where a.ds='2009-09-09'` which
> are useful when there are humongous number of columns in a table and want to
> select all columns except the partitions columns.
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