Question

C# 中调用存储过程报错“ 将参数值从 String 转换到 Int32 失败。”

protected void Button1_Click(object sender, EventArgs e)
{
//string sqlstr = "select * from xfgl where Flag in ('1') and (grono<=(select min(grono) from zb where flag<>2))";
//string sqlstr = "select * from xfgl where Flag in ('1','2','3','6')";
//SqlDataAdapter myda = new SqlDataAdapter(sqlstr, sqlcon);
//DataSet myds = new DataSet();
//sqlcon.Open();
DataSet MyDataSet = new DataSet();
System.Data.SqlClient.SqlDataAdapter DataAdapter = new System.Data.SqlClient.SqlDataAdapter();

if (sqlcon.State != ConnectionState.Open)
{
sqlcon.Open();
}

System.Data.SqlClient.SqlCommand myCommand = new System.Data.SqlClient.SqlCommand("starthouse", sqlcon);
myCommand.CommandType = CommandType.StoredProcedure;

myCommand.Parameters.Add("@GroNO", SqlDbType.Int);
myCommand.Parameters["@GroNO"].Value = "select GroNO from zb where grono = (select min(grono) from zb where flag<>2)";

myCommand.Parameters.Add("@errormessage", SqlDbType.VarChar, 255);
myCommand.Parameters["@errormessage"].Direction = ParameterDirection.Output;

myCommand.ExecuteNonQuery();
DataAdapter.SelectCommand = myCommand;

String Returnsql;
Returnsql = myCommand.Parameters["@errormessage"].Value.ToString();
Returnsql = Returnsql.Trim();
if (Returnsql.Length > 0)
{
//Response.Write("<script>alert('错误信息"&Returnsql&"')</script>");
Response.Write("<script>alert('选房开始错误！')</script>");
}
else
{
Response.Write("<script>alert('选房开始成功！')</script>");
//Response.Redirect("qdgl.aspx");
}

//关闭连接
if (sqlcon.State == ConnectionState.Open)
{
sqlcon.Close();
}
//Page_Load(object sender, EventArgs e);
GridView1.DataBind();
}

Answer 1

myCommand.Parameters.Add("@GroNO", SqlDbType.Int);
myCommand.Parameters["@GroNO"].Value = "select GroNO from zb where grono = (select min(grono) from zb where flag<>2)";

@GroNO接受整型，但是你传的是字符串

Answer 2

myCommand.Parameters["@GroNO"].Value = "select GroNO from zb where grono = (select min(grono) from zb where flag<>2)";
Value 要赋值Int类型的、、、、