db-derby-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Sylvain Leroux (JIRA)" <j...@apache.org>
Subject [jira] Updated: (DERBY-4550) Using ij to copy data from one DB to an other
Date Tue, 16 Feb 2010 22:43:29 GMT

     [ https://issues.apache.org/jira/browse/DERBY-4550?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Sylvain Leroux updated DERBY-4550:
----------------------------------

    Attachment: DERBY-4550_2.sql
                DERBY-4550_2.diff

Concerning the PREPARE statement:
ij> prepare fred_conn.second_select as 'select * from t1'; 

>From the user point of view, I think it could be frustrating to discover that qualified
names are allowed, but only if it refers to the current connection.

Couldn't it be more consistent to:
1) only allow unqualified identifiers here, thus enforcing the fact that you only can create/remove
an identifier in the current connection's namespace.
2) /or/ allow qualified identifiers here, allowing implicitly to create identifiers in an
other connection's namespace.


After a second thought, the later has my favors. Since it made possible to create/use/remove
a prepared statement without requiring to explicitly switch connection:

ij> CONNECT '.....' AS alice_conn;
ij> CONNECT '....' AS fred_conn;
ij> PREPARE alice_conn.source_stmt AS 'SELECT * FROM T1';
ij> EXECUTE 'INSERT INTO T2 VALUES(?)' USING alice_conn.source.stmt;
ij> REMOVE alice_conn.source_stmt;

With that option, the above PREPARE statement has for meaning:
    " in the context of the connection alice_conn, prepare the statement 'SELECT * FROM T1'
"


I attach both a patch and sql example to demonstrate that option.

> Using ij to copy data from one DB to an other
> ---------------------------------------------
>
>                 Key: DERBY-4550
>                 URL: https://issues.apache.org/jira/browse/DERBY-4550
>             Project: Derby
>          Issue Type: Improvement
>          Components: Tools
>            Reporter: Sylvain Leroux
>            Assignee: Sylvain Leroux
>            Priority: Minor
>         Attachments: DERBY-4550.diff, DERBY-4550.sql, DERBY-4550_2.diff, DERBY-4550_2.sql
>
>
> It is possible to have open connections to several databases while running ij, but it
is not currently possible to copy data from one DB to an other one.
> Not only such a feature would allow to copy data between Derby databases. But, ij being
mostly DB agnostic, if will ease import/export from any JDBC compliant data source.
> See http://old.nabble.com/Using-IJ-to-copy-data-from-one-DB-to-an-other-one-td27598138.html

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.


Mime
View raw message