问题
I am using a long varchar column to store log information. Now I want to retrieve it to a string, in C#, using a DataReader. However, there is an error:
Request to retrieve BLOB column which had already been accessed. BLOB column may only be accessed once.
回答1:
Maybe this url will help you:
Retrieving ntext, text, or image Values
Best regards
来源：https://stackoverflow.com/questions/18483262/long-varchar-to-string