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."
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.
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. |
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. |
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