When converting the table into an earlier version under Access, the verification expression cannot be defined in this field, the conversion is unsuccessful, and the problem is discovered, the problem is on real-type fields, and the problem is not resolved. So the new table structure puts the data with the SQL statement, the conversion is successful, but when the program is called, it is found that it cannot complete the final result, and there is no error message. So converted the idea, handle the original table Change to the same surface structure, in turn, success, and everything OK after executing the program.
However, the problems encountered have not been resolved:
1. What is a verification expression? Is it impact on field definitions? Where is the impact of converting different versions?
2. How do I know what kind of verification expression is defined? Which field is defined?
