Should information_schema.columns.COMMENT be renamed to COLUMN_COMMENT? about trino

[kokosing]

To me it looks like a bug in Hue.

[ebyhr]

By the way, information_schema.tables doesn't have a column for comment. Is it not implemented intentionally?

presto:default> select *, table_comment from hive.information_schema.tables where table_name = 'test_comment';
 table_catalog | table_schema |  table_name  | table_type | table_comment 
---------------+--------------+--------------+------------+---------------
 hive          | default      | test_comment | BASE TABLE | NULL          

Although hidden table_comment column exists, it always returns NULL.

[findepi]

@ebyhr this was added in 9c9ac4e
In order to show real table comments, we would need to modify io.prestosql.metadata.MetadataListing#listTables so that it returns table names + comments.

[ebyhr]

I see, thank you for providing the information!
Let me change listTables (and perhaps listViews also) to get the comment in COMMENT ON statement tests.

[findepi]

Should information_schema.columns.COMMENT be renamed to COLUMN_COMMENT?

both exist now. let me close this

[jhjiang0]

which version could get this change, I download the newest(0.240) source, but
select * from mysql_test.information_schema.columns
there only
table_catalog | table_schema | table_name | column_name | ordinal_position | column_default | is_nullable | data_type | comment | extra_info
no one column named COLUMN_COMMENT ,
still need we change the source code ?

[findepi]

@jhjiang0 The COLUMN_COMMENT column in .information_schema.columns table is available at least since Presto 320.
Note that it won't show up in SELECT * -- it is hidden, because it is non standard column (the schema of information_schema is governed by the spec).
You need explicitly select it: SELECT COLUMN_COMMENT FROM mysql_test.information_schema.columns.
Please make sure you run the latest Presto from https://prestosql.io/download.html

[jhjiang0]

@findepi thank you for providing the information! I'm download from the chinese website, maybe then don't update to latest, I will try download your latest code test this problem. thanks!