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https://issues.apache.org/jira/browse/HIVE-19064?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17089675#comment-17089675
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David Mollitor commented on HIVE-19064:
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I too am looking at this problem, but I have gone a different path with it.
The first thing is that Hive need to remove the REGEX column feature: HIVE-23176
If you don't do this than it introduces a lot of subtle issues in regards to
determining if a column is a name with special characters or if it's a regex
value.
{quote}
column: implies identifier names can contain any character by using backticks
`col1`
standard: implies identifier names can contain any character by using double
quotes "col1"
{quote}
As I understand this, the user must specify which system they would like to
use. If you take a look at MySQL,
{quote}
* The identifier quote character is the backtick (`)
* If the ANSI_QUOTES SQL mode is enabled, it is also permissible to quote
identifiers within double quotation marks:
https://dev.mysql.com/doc/refman/8.0/en/identifiers.html
{quote}
So for MySQL, the default is backticks AND one can add quotes on the fly. This
implementation makes this an OR choice.
The grammar for MySQL is available online, you should check out how they do
this so that we're not re-inventing the wheel.
> Add mode to support delimited identifiers enclosed within double quotation
> --------------------------------------------------------------------------
>
> Key: HIVE-19064
> URL: https://issues.apache.org/jira/browse/HIVE-19064
> Project: Hive
> Issue Type: Improvement
> Components: Parser, SQL
> Affects Versions: 3.0.0
> Reporter: Jesus Camacho Rodriguez
> Assignee: Krisztian Kasa
> Priority: Major
> Attachments: HIVE-19064.01.patch, HIVE-19064.02.patch,
> HIVE-19064.03.patch, HIVE-19064.4.patch, HIVE-19064.5.patch,
> HIVE-19064.6.patch
>
>
> As per SQL standard. Hive currently uses `` (backticks). Default will
> continue being backticks, but we will support identifiers within double
> quotation via configuration parameter.
> This issue will also extends support for arbitrary char sequences, e.g.,
> containing {{~ ! @ # $ % ^ & * () , < >}}, in database and table names.
> Currently, special characters are only supported for column names.
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