Re: rsmd.getPrecision(i) + rsmd.isNullable(i)

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От Fernando Nasser
Тема Re: rsmd.getPrecision(i) + rsmd.isNullable(i)
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Msg-id 3EE7AC38.2060103@redhat.com
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Ответ на rsmd.getPrecision(i) + rsmd.isNullable(i)  (Jens Haberer <gock@gmx.de>)
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I think you want getColumnDisplaySize().

As Barry said, getPrecision is just for numeric fields.

Fernando


Jens Haberer wrote:
> when you create a table with a alphanumeric column you specify a length for
> this column
> every other database return this length when you perform the
> "getPrecision()" method for this column.
> what would you do if you'd like to make a java program which copies a table
> from database XXX into YYY
> and you don't know how long this alphanumeric column is???
>
> ----- Original Message -----
> From: "Barry Lind" <blind@xythos.com>
> To: "Jens Haberer" <gock@gmx.de>
> Cc: <pgsql-jdbc@postgresql.org>
> Sent: Monday, June 09, 2003 5:52 PM
> Subject: Re: [JDBC] rsmd.getPrecision(i) + rsmd.isNullable(i)
>
>
>
>>Jens,
>>
>> From the javadoc for ResultSetMetadata:
>>
>>getPrecision:  Get the designated column's number of decimal digits.
>>
>>The javadoc implies that getPrecision is only for numeric datatypes.
>>What does 'number of decimal digits' mean for a text column?
>>
>>As for the isNullable() return value, the driver has no way to determine
>>if the underlying column in the query is nullable or not, so it returns
>>the proper value in this case which is: 2 (columnNullableUnknown).
>>
>>thanks,
>>--Barry
>>
>>
>>Jens Haberer wrote:
>>
>>>Hello,
>>>
>>>i have follwing table:
>>>
>>>"s1" bpchar(12)
>>>"s23" numeric(5,2)
>>>"s12" varchar(12)
>>>"s93" timestamptz
>>>
>>>when i export the stucture of this table with a java program i get
>>
> following
>
>>>results:
>>>
>>>name type precision scale nullable (from the resultsetmetadata object)
>>>s1 1 0 0 2
>>>s23 2 5 2 2
>>>s12 12 0 0 2
>>>s93 93 0 0 2
>>>
>>>why is precision of "s1" 0?
>>>why is precision of "s12" 0?
>>>why ist nullable always 2? Other databases have 0 or 1!
>>>
>>>i tried lot of jdbc driver from http://jdbc.postgresql.org/download/
>>>
>>>greetings
>>>
>>>jens haberer
>>>
>>
>>
>>
>
>
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--
Fernando Nasser
Red Hat Canada Ltd.                     E-Mail:  fnasser@redhat.com
2323 Yonge Street, Suite #300
Toronto, Ontario   M4P 2C9


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