Solved

DB2 Lob Locator Problem

Posted on 2002-05-04
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1,543 Views
Last Modified: 2007-11-27
Hi,
We are connecting to DB2 database using TopLink3.6. We have the following table with blob columns.

CREATE TABLE Table1 (
col1 DECIMAL(10) NOT NULL,
blob1 BLOB(164000),
col2 DECIMAL(10) NOT NULL,
blob2 BLOB(164000)
)

This works fine with JDBC Level 1 driver. But, while using JDBC Level 2 driver, We are getting the following exception;

EXCEPTION [TOPLINK-4002] (3.6 JDK1.2): TOPLink.Public.Exceptions.DatabaseException
EXCEPTION DESCRIPTION: COM.ibm.db2.jdbc.DB2Exception: [IBM][CLI Driver][DB2/NT] SQL0423N Locator va
riable "1" does not currently represent any value. SQLSTATE=0F001

INTERNAL EXCEPTION: COM.ibm.db2.jdbc.DB2Exception: [IBM][CLI Driver][DB2/NT] SQL0423N Locator varia
ble "1" does not currently represent any value. SQLSTATE=0F001

ERROR CODE: -423
at TOPLink.Public.Exceptions.DatabaseException.sqlException(DatabaseException.java:221)
at TOPLink.Private.Helper.ConversionManager.convertObjectToByteArray(ConversionManager.java:
212)
at TOPLink.Private.Helper.ConversionManager.convertObject(ConversionManager.java:81)
at TOPLink.Private.DatabaseAccess.DatabasePlatform.convertObject(DatabasePlatform.java:594)
at TOPLink.Public.Mappings.SerializedObjectMapping.getAttributeValue(SerializedObjectMapping
.java:43)
at TOPLink.Public.Mappings.DirectToFieldMapping.valueFromRow(DirectToFieldMapping.java:474)
at TOPLink.Public.Mappings.DatabaseMapping.readFromRowIntoObject(DatabaseMapping.java:808)
at TOPLink.Private.Descriptors.ObjectBuilder.buildAttributesIntoObject(ObjectBuilder.java:16
8)
at TOPLink.Private.Descriptors.ObjectBuilder.buildObject(ObjectBuilder.java:320)
at TOPLink.Private.Descriptors.ObjectBuilder.buildObjectsInto(ObjectBuilder.java:368)
at TOPLink.Public.QueryFramework.ReadAllQuery.execute(ReadAllQuery.java:368)
at TOPLink.Public.QueryFramework.DatabaseQuery.execute(DatabaseQuery.java:394)
at TOPLink.Public.QueryFramework.ReadQuery.execute(ReadQuery.java:99)
at TOPLink.Public.PublicInterface.Session.internalExecuteQuery(Session.java:1628)
at TOPLink.Public.ThreeTier.ServerSession.internalExecuteQuery(ServerSession.java:543)
at TOPLink.Public.PublicInterface.Session.executeQuery(Session.java:921)
at TOPLink.Private.Indirection.QueryBasedValueHolder.instantiate(QueryBasedValueHolder.java:
45)
at TOPLink.Private.Indirection.DatabaseValueHolder.getValue(DatabaseValueHolder.java:62)
at TLTable1.toString(Unknown Source)

I used the Blob.getBlob() in my sample application to get that table data and that retrieves fine(ie, without using toplink) ..

have anybody faced this already or someone has an answer for it.

Thanks in advance for the help!!

-Senthil.

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Comment
Question by:iamsenthil
5 Comments
 
LVL 7

Accepted Solution

by:
waynezhu earned 500 total points
Comment Utility
Senthil,

If you visit
"http://www-106.ibm.com/developerworks/java/jdk/" and
"http://www-106.ibm.com/developerworks/java/jdk/other/oldercode.html",
you will see, the available JDK versions (except on AIX)
are 1.1.x and 1.3.x. Also, it states
"We STRONGLY encourage developers to migrate to Java 2 version 1.3 as soon as possible, ...".

Other people may encounter similar problems as yours.
See this one:
"http://groups.google.com/groups?q=SQL0423N&hl=en&ie=UTF8&oe=UTF8&selm=95q0pb%24672%241%40news.chorus.net&rnum=1" where the JDK/JDBC 1.2 was used
same as what you have used.

Does IBM support JDK 1.2? If yes, call IBM for a fix. If
not, use IBM supported version instead.

Good Luck.

Wayne

PS. BTW, toplink 4.0 requires JDK 1.2 or above.
Does toplink 3.6 have the same requirement?
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Expert Comment

by:georgherdt
Comment Utility
Hi senthill,
if you still have this Problem there are two things you
should do for solving.

1.) Upgrade your DB2 installation to Fixpak 7, you can download this from the IBM website.

http://www-3.ibm.com/cgi-bin/db2www/data/db2/udb/winos2unix/support/v7fphist.d2w/report#WINDOWS

2.) check your code for the correct usage of the jdbc API.
What I mean is check youre Code for lines like these:
 Statement stmt;
  .... blah get my statement from connection ....
 stmt.executeQuery("delete from security.test where smb=0");
 
 instead you should write:
 stmt.executeUpdate("delete from security.test where
 smb=0");

 The same thing you should do for PreparedStatements.
 Whenever you use insert or update use executeUpdate(..) .

 In most cases the code above works, but it seems as this
 kind of usage has some sideeffect to the following queries.


 
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Expert Comment

by:modulo
Comment Utility
Dear: georgherdt

I've rejected your proposed answer as Experts Exchange holds an experiment to work without the answer button.

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Paragraph: Site Update for Wednesday, November 06, 2002

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Thanks !

modulo

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