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From "Laurent Goujon (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (DRILL-4420) C client and ODBC driver should move to using the new metadata methods provided by DRILL-4385
Date Fri, 09 Sep 2016 17:36:21 GMT

    [ https://issues.apache.org/jira/browse/DRILL-4420?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15477678#comment-15477678
] 

Laurent Goujon commented on DRILL-4420:
---------------------------------------

The C++ function {{std::string getSQLType(common::MinorType, common::DataMode)}} is the equivalent
of the Java method {{org.apache.drill.common.Types#getSqlTypeName(final MajorType)}} which
is was is populating values for {{ColumnMetadata::getDataType()}}, so the returned types should
be consistent across API. As for can these types be used for CAST or CREATE TABLE, I don't
see why it would not be the case, although I'm not sure to see a scenario when someone would
use the returned the SQL type to do a CAST. For CREATE TABLE, Drill doesn't it except for
CREATE TABLE AS (but you don't provide the schema), so is the question about that the type
returned by Drill valid for another vendor? I don't think we can guarantee that.

For signed vs unsigned, it's all about support by vendor. For example MySQL support both signed
and unsigned types: 
{code:sql}
CREATE TABLE tinyint_table(c1 TINYINT UNSIGNED)
{code}
The type is really {{TINYINT}}, and UNSIGNED is just a qualifier (like precision or radix),
with default being signed. For the ODBC driver it means the ODBC C type returned by the driver
might have to be adjusted (like returning {{SQLSMALLINT}} vs {{SQLUSMALLINT}})

> C client and ODBC driver should move to using the new metadata methods provided by DRILL-4385
> ---------------------------------------------------------------------------------------------
>
>                 Key: DRILL-4420
>                 URL: https://issues.apache.org/jira/browse/DRILL-4420
>             Project: Apache Drill
>          Issue Type: Sub-task
>            Reporter: Jacques Nadeau
>




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