Access insert into 语句问题

[zmm12]

protected void btnReferring_Click(object sender, EventArgs e)
{
string str = Session["Users"].ToString();
OleDbConnection cn = new OleDbConnection(ConfigurationManager.AppSettings["OLEDBCONNECTIONSTRING"].ToString() + System.Web.HttpContext.Current.Server.MapPath(ConfigurationManager.AppSettings["dbPath"]));

string sql = "insert into [Users]([Question],[Answer]) values ('"+ txtMatter.Text.Trim() +"','"+ txtResult.Text.Trim() +"') where UsersID='"+ str +"'";
string sql = "update [Users] set [Question]=@Question,[Answer]=@Answer where [UsersID]=@UsersID";
OleDbCommand cmd = new OleDbCommand(sql, cn);

cn.Open();

cmd.Parameters.Add("UsersID", OleDbType.VarChar).Value = str;
cmd.Parameters.Add("@Question", OleDbType.VarChar).Value = this.txtMatter.Text.Trim();
cmd.Parameters.Add("@Answer", OleDbType.VarChar).Value = this.txtResult.Text.Trim();
cmd.ExecuteNonQuery();
try
{
cmd.ExecuteNonQuery();
Response.Write("<script language=javascript>window.alert('设置成功！');</script>");
}
catch (OleDbException)
{
Response.Write("<script language=javascript>window.alert('设置失败！');</script>");
}
cn.Close();
}

SQL 语句的结束位置缺少分号 (;)。
说明: 执行当前 Web 请求期间，出现未处理的异常。请检查堆栈跟踪信息，以了解有关该错误以及代码中导致错误的出处的详细信息。

异常详细信息: System.Data.OleDb.OleDbException: SQL 语句的结束位置缺少分号 (;)。

源错误:


行 40: cmd.Parameters.Add("@Question", OleDbType.VarChar).Value = this.txtMatter.Text.Trim();
行 41: cmd.Parameters.Add("@Answer", OleDbType.VarChar).Value = this.txtResult.Text.Trim();
行 42: cmd.ExecuteNonQuery();
行 43: //try
行 44: //{

请问这是什么问题啊？我实在是搞不懂，我习惯怎么去做，请指点

[qawszx]

string sql = "update [Users] set [Question]= '"+this.txtMatter.Text.Trim()+"',[Answer]='"+this.txtResult.Text.Trim()+"' where [UsersID]='" +str+"'";

[shawn_yang]

string sql = "insert into [Users]([Question],[Answer]) values ( ' "+ txtMatter.Text.Trim() + " ', ' "+ txtResult.Text.Trim() + " ') where UsersID= ' "+ str + " ' ";


string sql = "update [Users] set [Question]=@Question,[Answer]=@Answer where [UsersID]=@UsersID ";
OleDbCommand cmd = new OleDbCommand(sql, cn);


到底是用哪个?

[netnpc]

string sql = "insert into [Users]([Question],[Answer]) values ( ' "+ txtMatter.Text.Trim() + " ', ' "+ txtResult.Text.Trim() + " ') where UsersID= ' "+ str + " ' ";
string sql = "update [Users] set [Question]=@Question,[Answer]=@Answer where [UsersID]=@UsersID ";
你可以声明2个相同的变量吗?

[yegengxing]

cmd.ExecuteNonQuery();
try
{
cmd.ExecuteNonQuery();

[qawszx]

回3楼，好像是不可以的，呵呵，你好细心哦。
如果想用参数，就用存储过程吧，不要直接用sql语句

[zmm12]

insert into 的，后面是注释的，还有，多了句 cmd.ExecuteNonQuery();

[jiangshun]

打断点一句一句的看