在MS Access中打开普及表时出现“无法多次定义字段”错误

Question

A few months ago, I updated a system that uses Pervasive v11. Only after that update, I started having problems with MS Access (2003 and 2016 tested) failing to link or import certain Pervasive tables via ODBC with the error, "Cannot define field more than once." There are no fields with duplicate names in any of the failing tables. I previously had no problems and now I suddenly do. The only changes that I'm aware of is to table structures. I even created a new, very simple table and still get that error.

I was informed by the system's retailer that this is no longer an issue as of Pervasive v13. How can I get around this problem without upgrading?

Answer 1

I'm not sure exactly what the absolute answer is, beyond upgrading, but I did find a workaround that may be acceptable (it is for me). Despite not being a problem before, the root issue appears to be with the table (and perhaps field) names. MS Access is not happy with underscores some of the time . Honestly, I just opened another table with two underscores in the name and it succeeded, but MS Access still fails to open my custom table with two underscores.

My workaround is to create new tables (or views for old tables) that have nothing other than straight alpha characters in the table name. If the view is simple enough (eg: select * from tablename ), then it is able to allow write access, which also allows MS Access to write data to that table via the view.

I'm speculating that this problem may extend to field names with underscores in some circumstances. Testing in PCC shows that giving an alias to a field does allow write access to the table. I mention this because I've seen some views cause a table to have read-only access when referenced via that view. I believe this happens when the view changes data-types or basic structure of a field. For example, the system has a table with dates stored as 6 characters ( 060118 ), but the view shows that as SQL_Date ( 20180601 ). That view does not allow adding or updating rows.

I'm sure some of what I just said is simple stuff that can be done with modern database systems and don't necessarily need explaining, but Pervasive has given me plenty of problems where other database systems would not, so I'm spelling out what I find that does work.

Answer 2

I just saw your question when I was having the same warning trying to convert a table to a database (.dbf) from Access. Simple tables I created myself had no problem, but data I had downloaded from data.gov (which I had cleaned and deleted fields) had trouble. I experimented by removing the underscores, as the answer above suggests and also removed dashes (- it doesn't like them). Then I changed the data type in the ID (primary key) field. It was automatically formatted as a number (which it was - a 10 digit integer). In design view, I changed the data type for the id (primary key) to 'text' and that fixed the problem. I had no trouble converting after that. I'm not sure why. Also, I had to shorten some of the longer field names.