PRB: DAO Oracle and the NUMBER Datatype

• Microsoft Visual Basic Enterprise Edition for Windows, version 5.0

SYMPTOMS

When using DAO/Jet to access an Oracle database, you get either blank rows back in a grid or rows filled with #DEFINE (when using Access).

CAUSE

This behavior is caused by DAO having a problem determining the datatype for Oracle columns defined as NUMBER.

RESOLUTION

This behavior is only exhibited when the Oracle columns have been defined as NUMBER. If you define the columns as NUMBER(38,0), which is the equivalent of just NUMBER, everything works as expected. When you use DAO/Jet to access an Oracle database, you need to specify the size (total digits) and precision for table columns of type NUMBER.

STATUS

Microsoft is researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

This problem was identified using Visual Basic 5.0 Enterprise edition, MDAC 1.5 (see the REFERENCES section below), and Oracle 7.3. You may see different behavior with different versions of these components. Following is an example of what will work and what will fail when creating an Oracle table that will be accessed by DAO/Jet.

This Oracle table definition will fail:

      CREATE TABLE daotest (item_number NUMBER PRIMARY KEY,
                            depot_number NUMBER);

      CREATE TABLE daotest (item_number NUMBER(38,0) PRIMARY KEY,
                            depot_number NUMBER(38,0));

REFERENCES

ORACLE: The Complete Reference by George Koch and Kevin Loney

For additional information, please see the following article in the Microsoft Knowledge Base:

   ARTICLE-ID: Q175018
   TITLE     : HOWTO: Acquire and Install the Microsoft Oracle ODBC Driver
               v2.0