Re: **SPAM** Re: Pb with linked tables on PG8

Many thanks for this very usefull information.

Luc
----- Original Message -----
From: Zlatko Matic
To: Ets ROLLAND ; pgsql-general(at)postgresql(dot)org
Sent: Thursday, June 09, 2005 6:52 PM
Subject: **SPAM** Re: [GENERAL] Pb with linked tables on PG8

Hello.

I have experoenced the same problem. It seems to be common problem with Access connectiong to ODBC data source. It seems that Access has some problems to determine primary key...
You should not use textual fields as primary key. Insted, add some bigserial (integer autoincrement field) into your tables and make such field primary key. Then relink your tables. This will solve your problem. Also, it is good to add timestamp field into tables.
Also, be aware that your tables names should not be too long, because if they are long you will have problems with relinking. Access would not relink correctly (preassuming that you will use DSN-less and relinking on each startup).

Bye.

Zlatko

For your information, this is explanation from MSDN:
"
ACC: "#Deleted" Errors with Linked ODBC Tables
View products that this article applies to.
Article ID : 128809
Last Review : May 6, 2003
Revision : 1.0

This article was previously published under Q128809
On this page
SYMPTOMS
CAUSE
RESOLUTION
MORE INFORMATION
Steps to Reproduce Behavior
APPLIES TO

SYMPTOMS
When you retrieve, insert, or update records in a linked ODBC table, each field in a record contains the "#Deleted" error message. When you retrieve, insert, or update records using code, you receive the error message "Record is deleted."
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CAUSE
The Microsoft Jet database engine is designed around a keyset-driven model. This means that data is retrieved, inserted, and updated based on key values (in the case of a linked ODBC table, the unique index of a table).

After Microsoft Access performs an insert or an update of a linked ODBC table, it uses a Where criteria to select the record again to verify the insert or update. The Where criteria is based on the unique index. Although numerous factors can cause the select not to return any records, most often the cause is that the key value Microsoft Access has cached is not the same as the actual key value on the ODBC table. Other possible causes are as follows:
. Having an update or insert trigger on the table, modifying the key value.
. Basing the unique index on a float value.
. Using a fixed-length text field that may be padded on the server with the correct amount of spaces.
. Having a linked ODBC table containing Null values in any of the fields making up the unique index.
These factors do not directly cause the "#Deleted" error message. Instead, they cause Microsoft Access to go to the next step in maintaining the key values, which is to select the record again, this time with the criteria based on all the other fields in the record. If this step returns more than one record, Microsoft Access returns the "#Deleted" message because it does not have a reliable key value to work with. If you close and re-open the table or choose Show All Records from the Records menu, the "#Deleted" errors are removed.

Microsoft Access uses a similar process to retrieve records from an linked ODBC table. First, it retrieves the key values and then the rest of the fields that match the key values. If Microsoft Access is not able to find that value again when it tries to find the rest of the record, it assumes that the record is deleted.
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RESOLUTION
The following are some strategies that you can use to avoid this behavior:
. Avoid entering records that are exactly the same except for the unique index.
. Avoid an update that triggers updates of both the unique index and another field.
. Do not use a Float field as a unique index or as part of a unique index because of the inherent rounding problems of this data type.
. Do all the updates and inserts by using SQL pass-through queries so that you know exactly what is sent to the ODBC data source.
. Retrieve records with an SQL pass-through query. An SQL pass-through query is not updateable, and therefore does not cause "#Delete" errors.
. Avoid storing Null values within any field making up the unique index of your linked ODBC table.

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MORE INFORMATION
Note: In Microsoft Access 2.0, linked tables were called attached tables.
Steps to Reproduce Behavior

1. Open the sample database Northwind.mdb (or NWIND.MDB. in Microsoft Access 2.0)
2. Use the Upsizing Tools to upsize the Shippers table.

NOTE: This table contains an AutoNumber field (or Counter field in Microsoft Access 2.0) that is translated on SQL Server by the Upsizing Tools into a trigger that emulates a counter.
3. Open the linked Shippers table and enter a new record. Make sure that the record you enter has the same data in the Company Name field as the previous record.
4. Press TAB to move to a new record. Note that the "#Deleted" error fills the record you entered.
5. Close and re-open the table. Note that the record is correct.
"
----- Original Message -----
From: Ets ROLLAND
To: pgsql-general(at)postgresql(dot)org
Sent: Thursday, June 09, 2005 1:19 PM
Subject: [GENERAL] Pb with linked tables on PG8

Hello !

I have an Access database using linked tables on PG 8.0.3 (on Windows 2003 server).
I use pgODBC 8.00.01.01.
Some tables appear like deleted !
In Access I see :
Categ : Table
vt_cat vt_libcat
#Supprimé #Supprimé
#Supprimé #Supprimé
#Supprimé #Supprimé
#Supprimé #Supprimé
#Supprimé #Supprimé
#Supprimé #Supprimé
#Supprimé #Supprimé
#Supprimé #Supprimé
(Supprmé means deleted in French)
I try to delete the link and recreate it, same problem !
I try a VACUUM FULL ANALYSE on the database, same problem !
How can I solve this problem ? Why ?
Many thanks for all your explainations.
Regards.

Luc