我知道这是一个相当常见的错误，但我似乎无法找到问题的根源。我试图使用存储过程添加学生的详细信息，因为必须将数据输入两个不同的表但我收到此错误：
System.Data.dll中出现'System.Data.SqlClient.SqlException'类型的异常，但未在用户代码中处理
其他信息：将数据类型nvarchar转换为int时出错。
on`myCommand.ExecuteNonQuery（）;
ASP.NET ：
<asp:SqlDataSource ID="courselist" runat="server"
ConnectionString='<%$ ConnectionStrings:ConnectionString %>'
SelectCommand="SELECT [course_name], [course_id] FROM [courses]">
</asp:SqlDataSource>
<asp:SqlDataSource ID="yearlist" runat="server"
ConnectionString='<%$ ConnectionStrings:ConnectionString %>'
SelectCommand="SELECT [year_id], [year_title] FROM [year]">
</asp:SqlDataSource>
<asp:SqlDataSource ID="advisor_tutor_list" runat="server"
ConnectionString='<%$ ConnectionStrings:ConnectionString %>'
SelectCommand="SELECT DISTINCT staff_records.f_name + ' ' + staff_records.l_name AS Name, staff_records.user_id FROM courses INNER JOIN staff_records ON courses.school = staff_records.school_id WHERE (courses.course_id = @course_id)">
<SelectParameters>
<asp:Parameter Name="course_id"></asp:Parameter>
</SelectParameters>
</asp:SqlDataSource>
<asp:SqlDataSource ID="status_list" runat="server"
ConnectionString='<%$ ConnectionStrings:ConnectionString %>'
SelectCommand="SELECT [status_id], [status] FROM [status]">
</asp:SqlDataSource>
<asp:SqlDataSource ID="current_academic_year" runat="server"
ConnectionString='<%$ ConnectionStrings:ConnectionString %>'
SelectCommand="SELECT [academic_year] FROM [academic_year]">
</asp:SqlDataSource>
<div class="row">
<div class="col-12">
<h1>Add Student Record</h1>
<h5 class="subheading">Please use the form below to add a student:</h5>
<div class="feedback blue" id="feedback" runat="server" visible="false">
<asp:Label ID="feedback_text" runat="server" Text=""></asp:Label>
</div>
</div>
</div>
<div class="row">
<div class="col-3">
<img id="img_preview" src="images/default_profile.jpg" />
</div>
<div class="col-9">
<div class="panel">
<h3>Fill out Student Details:</h3>
<h5>Profile Image:</h5>
<asp:FileUpload ID="newimage" runat="server" onpropertychange="changeImg(this.value)" />
<h5>First Name:</h5>
<asp:TextBox CssClass="full-width" ID="f_nametext" runat="server"></asp:TextBox>
<h5>Last Name:</h5>
<asp:TextBox CssClass="full-width" ID="l_nametext" runat="server"></asp:TextBox>
<h5>Password:</h5>
<asp:TextBox ID="p_wordtext" CssClass="inline-button" runat="server"></asp:TextBox>
<div class="button blue" id="generate_password_button">Create Password</div>
<h5>Course:</h5>
<asp:DropDownList CssClass="full-width" ID="courseddl" runat="server" DataSourceID="courselist" DataTextField="course_name" DataValueField="course_id" OnSelectedIndexChanged="courseddl_SelectedIndexChanged" AutoPostBack="true" OnDataBound="courseddl_DataBound"></asp:DropDownList>
<h5>Year:</h5>
<asp:DropDownList CssClass="full-width" ID="yearddl" runat="server" DataSourceID="yearlist" DataTextField="year_title" DataValueField="year_id"></asp:DropDownList>
<h5>Date of Birth:</h5>
<asp:TextBox ID="dob_calendar" CssClass="datepicker full-width" runat="server"></asp:TextBox>
<h5>Part Time / Full Time Status:</h5>
<asp:DropDownList CssClass="full-width" ID="enrolmentddl" runat="server">
<asp:ListItem>Full Time</asp:ListItem>
<asp:ListItem>Part Time</asp:ListItem>
</asp:DropDownList>
<h5>Personal Tutor:</h5>
<asp:DropDownList ID="tutorddl" CssClass="full-width" runat="server" DataSourceID="advisor_tutor_list" DataTextField="Name" DataValueField="user_id"></asp:DropDownList>
<h5>Advisor of Studies:</h5>
<asp:DropDownList ID="advisorddl" CssClass="full-width" runat="server" DataSourceID="advisor_tutor_list" DataTextField="Name" DataValueField="user_id"></asp:DropDownList>
<h5>Enrollment Status:</h5>
<asp:DropDownList ID="statusddl" CssClass="full-width" runat="server" DataSourceID="status_list" DataTextField="status" DataValueField="status_id"></asp:DropDownList>
<asp:DropDownList ID="academic_year_ddl" CssClass="full-width" runat="server" DataSourceID="current_academic_year" DataTextField="academic_year" DataValueField="academic_year" Visible="false"></asp:DropDownList>
<asp:Button ID="updatebutton1" runat="server" Text="Add Student" OnClick="updatebutton1_Click" />
</div>
</div>
</div>`
C＃代码隐藏：
protected void courseddl_SelectedIndexChanged(object sender, EventArgs e) {
string course_id = courseddl.SelectedValue;
advisor_tutor_list.SelectParameters["course_id"].DefaultValue = course_id;
advisor_tutor_list.DataBind();
}
protected void courseddl_DataBound(object sender, EventArgs e) {
courseddl.Items.Insert(0, new ListItem("- Select -", ""));
}
protected void updatebutton1_Click(object sender, EventArgs e) {
Random rand = new Random();
int newRand;
newRand = rand.Next(1, 99);
Random hashrand = new Random();
int newhashrand;
newhashrand = hashrand.Next(1000000000, int.MaxValue);
string f_name_data = f_nametext.Text;
string l_name_data = l_nametext.Text;
string pword_data = p_wordtext.Text;
string email_domain = "@uni.ac.uk";
string role = "5";
courseddl.DataBind();
string course_data = courseddl.SelectedValue;
string year_data = yearddl.SelectedValue;
string enrolment_data = enrolmentddl.SelectedValue;
string tutor_data = tutorddl.SelectedValue;
string advisor_data = advisorddl.SelectedValue;
string status_data = statusddl.SelectedValue;
academic_year_ddl.DataBind();
string academic_year = academic_year_ddl.SelectedValue;
string dob_text = dob_calendar.Text;
//check user has uploaded a file and filled in all fields
if (!newimage.HasFile || f_name_data == "" || l_name_data == "" || dob_text == "" || pword_data == "") {
feedback.Visible = true;
feedback_text.Text = "Please ensure you've uploaded an image and filled out all fields. ";
return;
}
DateTime dob_data = Convert.ToDateTime(dob_text);
string f_name_initial = f_nametext.Text.Substring(0, 1);
string UpPath = Server.MapPath("~/images");
string new_name = "";
Random r = new Random();
int rInt = r.Next(0, 10000);
if (!Directory.Exists(UpPath)) {
Directory.CreateDirectory(UpPath);
} else {
int imgSize = newimage.PostedFile.ContentLength;
string imgName = newimage.FileName;
new_name = rInt + imgName;
string imgPath = "images/" + new_name;
if (newimage.PostedFile.ContentLength > 1000000) {
Page.ClientScript.RegisterClientScriptBlock(typeof(Page), "Alert", "alert('File is too big.')", false);
} else {
newimage.SaveAs(Server.MapPath(imgPath));
}
}
string ConnectionString = WebConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
SqlConnection myConnection = new SqlConnection(ConnectionString);
myConnection.Open();
string query = "Execute AddStudent @password, @email, @role_id, @reset_hash, @student_id, @f_name, @l_name, @course_id, @year, @dob, @parttime_fulltime, @personal_tutor_id, @advisor, @status_id, @academic_year, @profile_image";
SqlCommand myCommand = new SqlCommand(query, myConnection);
myCommand.Parameters.AddWithValue("@password", EncryptPassword(pword_data));
myCommand.Parameters.AddWithValue("@email", f_name_initial + l_name_data + newRand + email_domain);
myCommand.Parameters.AddWithValue("@role_id", role);
myCommand.Parameters.AddWithValue("@reset_hash", newhashrand);
myCommand.Parameters.AddWithValue("@student_id", "");
myCommand.Parameters.AddWithValue("@f_name", f_name_data);
myCommand.Parameters.AddWithValue("@l_name", l_name_data);
myCommand.Parameters.AddWithValue("@course_id", course_data);
myCommand.Parameters.AddWithValue("@year", year_data);
myCommand.Parameters.AddWithValue("@dob", dob_data);
myCommand.Parameters.AddWithValue("@parttime_fulltime", enrolment_data);
myCommand.Parameters.AddWithValue("@personal_tutor_id", tutor_data);
myCommand.Parameters.AddWithValue("@advisor", advisor_data);
myCommand.Parameters.AddWithValue("@status_id", status_data);
myCommand.Parameters.AddWithValue("@academic_year", academic_year);
myCommand.Parameters.AddWithValue("@profile_image", new_name);
myCommand.ExecuteNonQuery();
myConnection.Close();
Response.Redirect("studentrecords.aspx");
}
private string EncryptPassword(string password) {
System.Security.Cryptography.SHA1 sha = System.Security.Cryptography.SHA1.Create();
string hashed = System.Convert.ToBase64String(sha.ComputeHash(System.Text.UnicodeEncoding.Unicode.GetBytes(password)));
return hashed.Length > 49 ? hashed.Substring(0, 49) : hashed;
}
存储过程：
CREATE PROCEDURE AddStudent
@password nvarchar(50),
@email nvarchar(50),
@role_id int,
@reset_hash nvarchar(50),
@student_id int,
@f_name nvarchar(50),
@l_name nvarchar(50),
@course_id int,
@year int,
@dob datetime,
@parttime_fulltime nvarchar(50),
@personal_tutor_id int,
@advisor int,
@status_id int,
@academic_year int,
@profile_image nvarchar(max)
AS
INSERT INTO users (password, email, role_id, reset_hash)
VALUES (@password, @email, @role_id, @reset_hash);
SET @student_id = SCOPE_IDENTITY()
INSERT INTO student_records (user_id, f_name, l_name, course_id, year, dob, parttime_fulltime, personal_tutor_id, advisor, status_id, academic_year, profile_image)
VALUES (@student_id, @f_name, @l_name, @course_id, @year, @dob, @parttime_fulltime, @personal_tutor_id, @advisor, @status_id, @academic_year, @profile_image)
Users表格结构：
user_id int
password nvarchar(50)
email nvarchar(50)
role_id int
reset_hash nvarchar(50)
student_records表格结构：
user_id int
f_name nvarchar(50)
l_name nvarchar(50)
course_id int
year int
dob datetime
parttime_fulltime nvarchar(50)
profile_image nvarchar(MAX)
personal_tutor_id int
status_id int
academic_year int
home_email nvarchar(256)
advisor int
非常感谢任何帮助。
答案 0 :(得分：0)
请试试这个
myCommand.Parameters.AddWithValue("@student_id", 0);
仔细检查所有这些属性，不应该向它们传递任何整数值
@role_id int
@student_id int
@course_id int
@year int
@personal_tutor_id int
@advisor int
@status_id int
@academic_year int
答案 1 :(得分：0)
数据库表中的以下某些列可能是int，假设为nvarchar
@email nvarchar(50),
@reset_hash nvarchar(50),
@f_name nvarchar(50),
@l_name nvarchar(50),
@parttime_fulltime nvarchar(50),
@profile_image nvarchar(max)
答案 2 :(得分：0)
你不能像这样传递Student_id
myCommand.Parameters.AddWithValue("@student_id", "");
你必须改为传递一个int值。