我再次遇到另一个问题。我试图使用DataReader从数据库中获取数据,但是当我测试代码时出现错误。谁能帮我吗?错误发生在此行:DataReader IndexOutofRangeException未被用户代码处理
chkAssess = readAssess [columnName] .ToString();
下面的代码片段:
public string CheckAssess(string emailAddress, string columnName)
{
string chkAssess = "";
SqlDataReader readAssess;
//readAssess = new SqlDataReader();
string MgrAssessQry = "SELECT '"+columnName+"' FROM tblAllUsers";
//MgrAssessQry += " WHERE email ='" + emailAddress + "'";
SqlCommand cmdReadAssess = new SqlCommand(MgrAssessQry, cn);
cn.Open();
readAssess = cmdReadAssess.ExecuteReader();
while(readAssess.Read())
{
// Add the rows
chkAssess = readAssess[columnName].ToString();
}
return chkAssess;
}