Have a table (SQL Server 2008) that the user wants to record a fixed 8 character string in. At first glance, a CHAR seems the obvious selection since this value (an 8 character ID, two alpha ...

int (*callback) (void*,int,char**,char**) 回调函数，通常用来接收SQL语句查询到的数据； void *, 这个参数作为回调函数中的第一个参数； ...

Another one of these choices... to go with a char or varchar for a field. Not really an issue with space since we are only looking at a couple of thousand records or so but just wondering what the ...