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From yves pielusenet <yvespieluse...@free.fr>
Subject Re: Retreive colummn name of a table from java
Date Fri, 15 Sep 2006 07:23:38 GMT
Ok thank you Francois (are you french as me ?) :)
I understand now. It should be specified into this doc :
http://wiki.apache.org/db-derby/ListTableColumns

that schemaname='SYS' is for the example but if we want to retreive
columns of a personal table, we should use schemaname='APP' :)

Le vendredi 15 septembre 2006 à 00:08 -0700, Francois Orsini a écrit :
> All the Derby database system tables reside in the 'SYS' schema
> whereas the default "user" schema is named 'APP'. When you log in to
> derby, the default schema where the objects are created is 'APP'.
> 
> In your (own) query, you had not restricted the query against any
> particular schema, hence it picked it up.
> 
> On 9/15/06, yves pielusenet <yvespielusenet@free.fr> wrote:
>         Thank you Francois :)
>         It works with that schema. but what is the difference between
>         APP and 
>         SYS ?
>         And the result is the same as my statement. Is my own wrong ?
>         
>         Le jeudi 14 septembre 2006 à 23:51 -0700, Francois Orsini a
>         écrit :
>         > Ok - Yves, can you try against the schema 'APP' (default)
>         such as: 
>         >
>         > ij> select columnnumber, columnname, columndatatype
>         >    from sys.systables t, sys.syscolumns, sys.sysschemas s
>         >    where tableid=referenceid and t.schemaid=s.schemaid
>         >      and schemaname='APP' and tablename='DATA' 
>         >    order by columnnumber;
>         >
>         > On 9/14/06, yves pielusenet <yvespielusenet@free.fr> wrote:
>         >         Yes I have tried it but there is any rows back :( 
>         >
>         >         ij> select columnnumber, columnname, columndatatype
>         >            from sys.systables t, sys.syscolumns,
>         sys.sysschemas s
>         >            where tableid=referenceid and
>         t.schemaid=s.schemaid
>         >              and schemaname='SYS' and tablename='DATA'
>         >            order by columnnumber;
>         >         COLUMNNUMB&|COLUMNNAME|COLUMNDATATYPE
>         >
>         ------------------------------------------------------------------------------------------------------------------------------------------------------------

>         >
>         >         0 lignes sélectionnées
>         >
>         >
>         >         Le jeudi 14 septembre 2006 à 15:37 -0700, Francois
>         Orsini a
>         >         écrit :
>         >         > Have you tried the following below?
>         >         >
>         >         > ij> select columnnumber, columnname,
>         columndatatype
>         >         >    from sys.systables t, sys.syscolumns,
>         sys.sysschemas s
>         >         >    where tableid=referenceid and
>         t.schemaid=s.schemaid
>         >         >      and schemaname='SYS' and tablename='DATA'
>         >         >    order by columnnumber;
>         >         >
>         >         > are you getting any rows back?
>         >         >
>         >         > On 9/14/06, yves pielusenet
>         <yvespielusenet@free.fr> wrote:
>         >         >         after tests I found this statement :
>         >         >         ij> select columnname, columnnumber from
>         >         sys.systables,
>         >         >         sys.syscolumns where referenceid=tableid
>         and
>         >         tablename='DATA'
>         >         >         order by columnnumber;
>         >         >
>         >         >         which works well for me :)
>         >         >
>         >         >         do you see something wrong ?
>         >         >
>         >         >
>         >         >         Le jeudi 14 septembre 2006 à 15:16 -0700,
>         Francois
>         >         Orsini a
>         >         >         écrit :
>         >         >         > Yes,
>         >         >         >
>         >         >         > It all depends how you created the table
>         - have
>         >         you tried
>         >         >         running the
>         >         >         > query by specifying you table name in
>         uppercase
>         >         such as:
>         >         >         > j> select columnnumber, columnname,
>         columndatatype
>         >         >         >    from sys.systables t, sys.syscolumns,
>         >         sys.sysschemas s
>         >         >         >    where tableid=referenceid and
>         >         t.schemaid=s.schemaid
>         >         >         >      and schemaname='SYS' and
>         tablename='DATA'
>         >         >         >    order by columnnumber;
>         >         >         >
>         >         >         > _or_ you can also run "select * from
>         >         sys.systables" and find
>         >         >         out if
>         >         >         > your table appears in the list being
>         >         retrieved...then check
>         >         >         the actual
>         >         >         > table identifier (aka name)...
>         >         >         >
>         >         >         > Hope this helps a bit,
>         >         >         >
>         >         >         > --francois
>         >         >         >
>         >         >         > On 9/14/06, yves pielusenet
>         >         <yvespielusenet@free.fr> wrote:
>         >         >         >         Hello,
>         >         >         >         I read this :
>         >         >         >
>         >         http://wiki.apache.org/db-derby/ListTableColumns
>         >         >         > 
>         >         >         >         but I can't retreive the column
>         of my
>         >         table 'data'.
>         >         >         Here is
>         >         >         >         what i
>         >         >         >         tested :
>         >         >         >         ij> select columnnumber,
>         columnname,
>         >         columndatatype
>         >         >         >             from sys.systables t,
>         sys.syscolumns,
>         >         >         sys.sysschemas s
>         >         >         >             where tableid=referenceid
>         and
>         >         >         t.schemaid=s.schemaid
>         >         >         >               and schemaname='SYS' and
>         >         tablename='data'
>         >         >         >             order by columnnumber;
>         >         >         >
>         >         >         >         And the result is :
>         >         >         >
>         >         >         >         COLUMNNUMB&|COLUMNNAME|
>         COLUMNDATATYPE
>         >         >         >
>         >         >
>         >
>         ------------------------------------------------------------------------------------------------------------------------------------------------------------

>         >         >         >
>         >         >         >         0 lignes sélectionnées
>         >         >         >
>         >         >         >         How can I do ?
>         >         >         >
>         >         >         >         thanks,
>         >         >         >
>         >         >         >         --
>         >         >         >         yves piel
>         >         >         >
>         >         >         >
>         >         >         >
>         >         >
>         >         >
>         >
>         >
>         
> 


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