嗨，我正在尝试从网页的 excel 电子表格将数据加载到 sql 中，我收到“无法将类型隐式转换为 ' string' decimal”错误我尝试了不同的方法来纠正此问题，但没有任何效果。
namespace CarpartsStore.Dealers
{
partial class DealerHome : System.Web.UI.Page
{
protected void ButtonUpload_Click(object sender, System.EventArgs e)
{
PanelUpload.Visible = true;
PanelView.Visible = false;
PanelImport.Visible = false;
}
protected OleDbCommand ExcelConnection()
{
// Connect to the Excel Spreadsheet
string xConnStr = "Provider=Microsoft.Jet.OLEDB.4.0;" + "Data Source=" + Server.MapPath("~/ExcelImport.xls") + ";" + "Extended Properties=Excel 8.0;";
// create your excel connection object using the connection string
OleDbConnection objXConn = new OleDbConnection(xConnStr);
objXConn.Open();
// use a SQL Select command to retrieve the data from the Excel Spreadsheet
// the "table name" is the name of the worksheet within the spreadsheet
// in this case, the worksheet name is "Members" and is coded as: [Members$]
OleDbCommand objCommand = new OleDbCommand("SELECT * FROM [Products$]", objXConn);
return objCommand;
}
protected void ButtonView_Click(object sender, System.EventArgs e)
{
PanelUpload.Visible = false;
PanelView.Visible = true;
PanelImport.Visible = false;
// Create a new Adapter
OleDbDataAdapter objDataAdapter = new OleDbDataAdapter();
// retrieve the Select command for the Spreadsheet
objDataAdapter.SelectCommand = ExcelConnection();
// Create a DataSet
DataSet objDataSet = new DataSet();
// Populate the DataSet with the spreadsheet worksheet data
objDataAdapter.Fill(objDataSet);
// Bind the data to the GridView
GridViewExcel.DataSource = objDataSet.Tables[0].DefaultView;
GridViewExcel.DataBind();
}
protected void ButtonImport_Click(object sender, System.EventArgs e)
{
PanelUpload.Visible = false;
PanelView.Visible = false;
PanelImport.Visible = true;
LabelImport.Text = "";
// reset to blank
// retrieve the Select Command for the worksheet data
OleDbCommand objCommand = new OleDbCommand();
objCommand = ExcelConnection();
// create a DataReader
OleDbDataReader reader;
reader = objCommand.ExecuteReader();
// create variables for the spreadsheet columns
int ProductID = 0;
int MakeID = 0;
int DealerID = 0;
string PartNumber = "";
string Description = "";
decimal UnitCost = 0.00M;
decimal Postage = 0.00M;
int QtyAvailable = 0;
string UserName = "";
string Make = "";
int counter = 0;
// used for testing your import in smaller increments
while (reader.Read())
{
counter = counter + 1;
// counter to exit early for testing...
// set default values for loop
ProductID = 0;
MakeID = 0;
DealerID = 0;
PartNumber = GetValueFromReader(reader,"PartNumber");
Description = GetValueFromReader(reader,"Description");
UnitCost = GetValueFromReader(reader,"UnitCost");
Postage = GetValueFromReader(reader, "Postage");
QtyAvailable = GetValueFromReader(reader,"QtyAvailable");
UserName = GetValueFromReader(reader,"UserName");
Make = GetValueFromReader(reader,"Make");
// Insert any required validations here...
MakeID = GetMakeID(Make);
DealerID = GetDealerID(UserName);
//retrieve the MakeID
ProductID = ImportIntoProducts(PartNumber, Description, UnitCost, Postage, QtyAvailable, MakeID, DealerID);
LabelImport.Text = LabelImport.Text + ProductID + PartNumber + " " + Description + " " + UnitCost + " " + Postage + " " + QtyAvailable + " " + UserName + " Make_id: " + MakeID + " " + Make + "<br>";
//If counter > 2 Then ' exit early for testing, comment later...
// Exit While
//End If
}
reader.Close();
}
protected string GetValueFromReader(OleDbDataReader myreader, string stringValue)
{
object val = myreader[stringValue];
if (val != DBNull.Value)
return val.ToString();
else
return "";
}
protected void ButtonUploadFile_Click(object sender, System.EventArgs e)
{
if (FileUploadExcel.HasFile)
{
try
{
// alter path for your project
FileUploadExcel.SaveAs(Server.MapPath("~/ExcelImport.xls"));
LabelUpload.Text = "Upload File Name: " +
FileUploadExcel.PostedFile.FileName + "<br>" +
"Type: " + FileUploadExcel.PostedFile.ContentType +
" File Size: " + FileUploadExcel.PostedFile.ContentLength +
" kb<br>";
}
catch (System.NullReferenceException ex)
{
LabelUpload.Text = "Error: " + ex.Message;
}
}
else
{
LabelUpload.Text = "Please select a file to upload.";
}
}
protected int GetMakeID(string MakeName)
{
int makeID = 0;
try
{
CarpartsStore.DataSets.SSSProductsDataSetTableAdapters.MakesTableAdapter SSAdapter = new CarpartsStore.DataSets.SSSProductsDataSetTableAdapters.MakesTableAdapter();
SSSProductsDataSet.MakesDataTable SSDataTable = null;
SSDataTable = SSAdapter.GetMakeByName(MakeName);
// see if the category already exists in the table, if not insert it
if (SSDataTable != null)
{
if (SSDataTable.Rows.Count > 0)
{
if (SSDataTable[0].MakeID > 0)
{
makeID = SSDataTable[0].MakeID;
}
}
}
if (makeID == 0)
{
// if it is still 0, then insert it into the table
// retrieve the identity key category_id from the insert
makeID = (int)SSAdapter.InsertMakeQuery(MakeName);
// if this fails to return the proper category_id, make sure to
// set the InsertCategoryQuery ExecuteMode Property to Scalar
}
return makeID;
}
catch (System.NullReferenceException ex)
{
LabelImport.Text = LabelImport.Text + ex.Message;
return 0;
}
}
protected int GetDealerID(string UserName)
{
int DealerID = 0;
try
{
CarpartsStore.DataSets.SSSProductsDataSetTableAdapters.DealersTableAdapter SSAdapter = new CarpartsStore.DataSets.SSSProductsDataSetTableAdapters.DealersTableAdapter();
SSSProductsDataSet.DealersDataTable SSDataTable = null;
SSDataTable = SSAdapter.GetDealersByUserName(UserName);
// see if the User already exists in the table, if not insert it
if (SSDataTable != null)
{
if (SSDataTable.Rows.Count > 0)
{
if (SSDataTable[0].DealerID > 0)
{
DealerID = SSDataTable[0].DealerID;
}
}
}
if (DealerID == 0)
{
// if it is still 0, then insert it into the table
// retrieve the identity key category_id from the insert
DealerID = 0;
// if this fails to return the proper category_id, make sure to
// set the InsertCategoryQuery ExecuteMode Property to Scalar
}
return DealerID;
}
catch (System.NullReferenceException ex)
{
LabelImport.Text = LabelImport.Text + ex.Message;
return 0;
}
}
protected int ImportIntoProducts(string PartNumber, string Description, decimal UnitCost, decimal Postage, int QtyAvailable, int MakeID, int DealerID)
{
// make sure values don't exceed column limits
PartNumber = Left(PartNumber, 50);
Description = Left(Description, 300);
UnitCost = Convert.ToDecimal(UnitCost);
int ProductID = 0;
try
{
CarpartsStore.DataSets.SSSProductsDataSetTableAdapters.ProductsTableAdapter SSAdapter = new CarpartsStore.DataSets.SSSProductsDataSetTableAdapters.ProductsTableAdapter();
SSSProductsDataSet.ProductsDataTable SSDataTable = null;
SSDataTable = SSAdapter.GetProductsByPartNumberDealer(PartNumber, DealerID);
// see if the category already exists in the table, if not insert it
if (SSDataTable != null)
{
if (SSDataTable.Rows.Count > 0)
{
if (SSDataTable[0].ProductID > 0)
{
ProductID = SSDataTable[0].ProductID;
LabelImport.Text = LabelImport.Text + "<font color=blue>PartNumber Found, Not Imported: " + " ID: " + ProductID + " " + PartNumber + " " + Description + "" + UnitCost + "" + Postage + ".</font><br>";
}
}
}
if (ProductID == 0)
{
// if it is still 0, then insert it into the table
// retrieve the identity key ProductID from the insert
ProductID = Convert.ToInt32(SSAdapter.InsertProductQuery(PartNumber, Description,UnitCost, Postage, QtyAvailable, MakeID, DealerID));
LabelImport.Text = LabelImport.Text + "<font color=white>Part Number Imported: " + " ID: " + ProductID + " " + PartNumber + " " + Description + " Cost: " + UnitCost + ".</font><br>";
}
return ProductID;
}
catch (System.NullReferenceException ex)
{
LabelImport.Text = LabelImport.Text + "<font color=red>" + ex.Message + "</font><br>";
return 0;
}
}
// http://www.mgbrown.com/PermaLink68.aspx
public static string Left(string text, int length)
{
if (length < 0)
throw new ArgumentOutOfRangeException("length", length, "length must be > 0");
else if (length == 0 || text.Length == 0)
return "";
else if (text.Length <= length)
return text;
else
return text.Substring(0, length);
}
}
}