Question

c#错误：“至少一个参数没有被指定值。”，怎么改正呢？ 大家帮帮忙吧

OleDbConnection dbconn1 = new OleDbConnection(@"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=mydb.accdb");
dbconn1.Open();
OleDbCommand cmd_1 = dbconn1.CreateCommand();
cmd_1.CommandText = "select User from User_inf where User=na";
OleDbDataReader result = cmd_1.ExecuteReader();

Answer 1

SQL语句这么写：加上单引号 select User from User_inf where User=‘na’

Answer 2

嗯，是sql语句的问题。