Coexistence of entity and ghost Value

It is normal to import and export data in the system. It is annoying to export data in Multiple Buckets. For example, importing SQL from DBF is importing DBF from SQL, this is the case.

In data import and export, there are common good varieties:

First, the exported data is too long and cannot be imported to cause errors.

Second, special characters are the most concealed errors. Some databases are not compatible with special characters such as carriage return and line breaks, which can also cause data export errors. The cause of this error is hard to find

An error occurred while exporting data from SQL.ProgramIs not caused by the above two situations. It is very difficult to find the cause, so the benzene method is also very effective: Tracking and comparison, and finally found that a field contains the "\ 0" ending character, this is where the guess error is. There is no problem with the replace test. "\ 0" is a special character in the DOS environment called ascii0, that is, a null value. In SQL, it is assumed that it is a null value or a "ghost value ". This is interesting. The data with values in this field is still very long. Now it is confusing to coexist with the "\ 0" ghost value.

In short, I found the cause and did not find the real cause. Let's make a reminder here.