Search Postgresql Archives

Re: Pb with linked tables on PG8

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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

Article ID : 128809
Last Review : May 6, 2003
Revision : 1.0
This article was previously published under Q128809

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."

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.

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.

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 -----
Sent: Thursday, June 09, 2005 1:19 PM
Subject: 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

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [Postgresql Jobs]     [Postgresql Admin]     [Postgresql Performance]     [Linux Clusters]     [PHP Home]     [PHP on Windows]     [Kernel Newbies]     [PHP Classes]     [PHP Books]     [PHP Databases]     [Postgresql & PHP]     [Yosemite]
  Powered by Linux