Hi,

When you say you are adding a new column to one of your tables, are you saying you are changing your DDF?

Would it be possible to see the before and after changes you have made?

Regards,
Tom

Tom,

Thanks for your rapid response.

I have never been near the DDF (as far as I know).  I added the columns to the table using ALTER TABLE sql statement.

I'm not sure I am able to give you a before and after scenario - other than a list of columns in the table.  For what it is worth the table has 104 columns in it!

I appreciate your assistance

Regards

Jeremy

Are you issuing and ALTER TABLE statement with an IN DICTIONARY clause?  
Are you trying to add fields to the DDFs that already exist in the Btrieve file?

Mirtheil
Certified Pervasive Developer
Certified Pervasive Technician
http://www.mirtheil.com

Mirtheil,

No, I am not issuing the ALTER TABLE statement with an IN DICTIONARY clause.

Let me try an lay down the exact steps I have followed to date:

1. I created the table from within the Pervasive Control centre using SQL (not the GUI)
2. I imported all of the data from an existing MS Access .mdb file.
3.  Using the ALTER TABLE statement I added the new columns to the existing table

I have not touched the DDFs

Thanks for your assistance

Regards

Jeremy

Actually, issuing an ALTER TABLE will modify the DDFs.  
Do the DDFs pass a COnsistency Check before or after you issue the ALTER TABLE statement?

Mirtheil
Certified Pervasive Developer
Certified Pervasive Technician
http://www.mirtheil.com

Hi Mirtheil,

Yes, it passed consistency checks after the columns were added

Regards

Jeremy

Did it pass the consistency check before you issue the ALTER TABLE?
Post your ALTER TABLE statement.  
I tried with the following simple statements and do not see the behavior you are seeing.

With the results being:

Mirtheil
Certified Pervasive Developer
Certified Pervasive Technician
http://www.mirtheil.com

Mirtheil,

Here is the ALTER TABLE Statement:


The problem only seems to occur in the one table (Projects)

Cheers

Jeremy

I'm not sure why it would be occurring.  It's almost like there was a field there and by adding the column it got some of that old data.  
You might use an UPDATE statement to clear it out.  Something like:
UPDATE Projects set ContractDURUnits = '
or
UPDATE Projects set ContractDURUnits = null
Depending on what you want to be in the field.

Mirtheil
Certified Pervasive Developer
Certified Pervasive Technician
http://www.mirtheil.com

The problem only seems to occur for varchar and longvarchar type columns.

Your suggestion will probably be an adequate work-around but I am still a little worried about the root-cause of the problem.

Of all the tables in the database, the Project table is by far the largest with the most records (around 10,000) and the most number of columns (and hence the biggest record length).  Could this have anything to do with it?

Regards


Jeremy

It could. What's the actual size of the record length?  What's the field type before these varchar/longvarchar fields?  

Mirtheil
Certified Pervasive Developer
Certified Pervasive Technician
http://www.mirtheil.com

The record length is:  2941
The Field adjacent to the new fields is called ParentID and is   type Integer

Did you get any further with this?

Tom,

No, I haven't had any success getting a resolution.  Very frustrating!

Regards

Jeremy

Jeremy,

What I'm wondering is whether your DDF is in synch with the underlying data table.  The DDF is the definition of your table for the purposes of relational/SQL access.

You mention that the record length is 2941 - where are you getting that value from?

Regards,
Tom

Tom,

In the Control Center, I right-hand click on the Table and select Properties.

Regards

Jeremy

What's the record size and page size for the underlying Btrieve file?  Can you post a BUTIL -STAT report?

Mirtheil
Certified Pervasive Developer
Certified Pervasive Technician
http://www.mirtheil.com

Tom,

I'm probably showing my ignorance with this question!!!  Is there meant to be one DDF file per table?

Cheers

Jeremy

Hi Jeremy,

The DDF has the information for all the tables within each 'database'.  

What Mirtheil is asking is whether the table properties in the control center agrees with the BUTIL -STAT report - if there is a difference in could explain why you are having data problems.

Regards,
Tom
 

Sorry about that.  Tom is right there DDFs (FILE, FIELD, and INDEX) describe each table and present the logical view of each Btrieve file.  Each Btrieve file is typically defined as one table within the DDFs and a set of DDF defines multiple tables.  You can get the file name of the underlying Btrieve file in the Properties tab. Also, BUTIL is a command line tool provided by Pervasive and is installed in the PVSW\BIN directory (along with the rest of the Pervasive components).

Mirtheil
Certified Pervasive Developer
Certified Pervasive Technician
http://www.mirtheil.com