![gvDetails]( "gvDetails")
本文介绍了不允许从数据类型nvarchar到varbinary（max）的隐式转换。使用CONVERT函数运行此查询。的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述 using System;using System.Collections.Generic;using System.Linq;using System.Web;using System.Web.UI;using System.Web.UI.WebControls;using System.Data;using System.Data.SqlClient;using System.Configuration;using System.IO;using System.Web.UI.WebControls;public partial class Medicaldetails : System.Web.UI.Page{ SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["hospitalConnectionString"].ToString()); protected void Page_Load(object sender, EventArgs e) { if (!Page.IsPostBack) { BindEmployeeDetails(); } } protected void BindEmployeeDetails() { con.Open(); SqlCommand cmd = new SqlCommand("Select * from medicine", con); SqlDataAdapter da = new SqlDataAdapter(cmd); DataSet ds = new DataSet(); da.Fill(ds); con.Close(); if (ds.Tables[0].Rows.Count > 0) { gvDetails.DataSource = ds; gvDetails.DataBind(); } else { ds.Tables[0].Rows.Add(ds.Tables[0].NewRow()); gvDetails.DataSource = ds; gvDetails.DataBind(); con.Close(); int columncount = gvDetails.Rows[0].Cells.Count; gvDetails.Rows[0].Cells.Clear(); gvDetails.Rows[0].Cells.Add(new TableCell()); gvDetails.Rows[0].Cells[0].ColumnSpan = columncount; gvDetails.Rows[0].Cells[0].Text = "No Records Found"; } } protected void gvDetails_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e) { gvDetails.EditIndex = -1; BindEmployeeDetails(); } protected void gvDetails_RowEditing(object sender, GridViewEditEventArgs e) { gvDetails.EditIndex = e.NewEditIndex; BindEmployeeDetails(); } protected void gvDetails_RowUpdating(object sender, GridViewUpdateEventArgs e) { int s_no = Convert.ToInt32(gvDetails.DataKeys[e.RowIndex].Values["s_no"].ToString()); TextBox bill_number = (TextBox)gvDetails.Rows[e.RowIndex].FindControl("bill_number"); TextBox date = (TextBox)gvDetails.Rows[e.RowIndex].FindControl("txt_date"); TextBox shop_name = (TextBox)gvDetails.Rows[e.RowIndex].FindControl("txt_shopname"); TextBox ammount = (TextBox)gvDetails.Rows[e.RowIndex].FindControl("txt_amt"); con.Open(); SqlCommand cmd = new SqlCommand("update medicine set bill_number='" + bill_number.Text + "', date = '" + date.Text + "', shop_name ='" + shop_name.Text + "', ammount = '" + ammount.Text + "' where s_no=" + s_no, con); cmd.ExecuteNonQuery(); con.Close(); gvDetails.EditIndex = -1; BindEmployeeDetails(); } protected void gvDetails_RowDeleting(object sender, GridViewDeleteEventArgs e) { int s_no = Convert.ToInt32(gvDetails.DataKeys[e.RowIndex].Values["s_no"].ToString()); con.Open(); SqlCommand cmd = new SqlCommand("delete from medicine where s_no =" + s_no, con); int result = cmd.ExecuteNonQuery(); con.Close(); if (result == 1) { BindEmployeeDetails(); } } protected void gvDetails_RowCommand(object sender, GridViewCommandEventArgs e) { if (e.CommandName.Equals("AddNew")) { TextBox bill_number = (TextBox)gvDetails.FooterRow.FindControl("txt_bill"); TextBox date = (TextBox)gvDetails.FooterRow.FindControl("txtDate"); TextBox shop_name = (TextBox)gvDetails.FooterRow.FindControl("txt_shopname11"); TextBox Ammount = (TextBox)gvDetails.FooterRow.FindControl("txt_amt11"); FileUpload fileupd2 = (FileUpload)gvDetails.FooterRow.FindControl("FileUpload1_test"); FileUpload fileupd1 = (FileUpload)gvDetails.FooterRow.FindControl("FileUpload_bill"); FileUpload fileupd = (FileUpload)gvDetails.FooterRow.FindControl("FileUpload_pre"); con.Open(); SqlCommand cmd = new SqlCommand("insert into medicine(bill_number, dt, shop_name, Ammount,pres, medicine_bills, test_bills ) values(@bill_number, @dt, @shop_name, @Ammount, @pres, @medicine_bills, @test_bills)", con); cmd.Connection = con; cmd.Parameters.AddWithValue("@bill_number", bill_number.Text); cmd.Parameters.AddWithValue("@dt", date.Text); cmd.Parameters.AddWithValue("@shop_name", shop_name.Text); cmd.Parameters.AddWithValue("@Ammount", Ammount.Text); cmd.Parameters.AddWithValue("@pres", fileupd.FileName); cmd.Parameters.AddWithValue("@medicine_bills", fileupd1.FileName); cmd.Parameters.AddWithValue("@test_bills", fileupd2.FileName); int result = cmd.ExecuteNonQuery(); con.Close(); if (result == 1) { BindEmployeeDetails(); } else { } } } protected void gvDetails_SelectedIndexChanged(object sender, EventArgs e) { FileUpload fileupd2 = (FileUpload)gvDetails.FooterRow.FindControl("FileUpload1_test"); FileUpload fileupd1 = (FileUpload)gvDetails.FooterRow.FindControl("FileUpload_bill"); FileUpload fileupd = (FileUpload)gvDetails.FooterRow.FindControl("FileUpload_pre"); string filename = Path.GetFileName(fileupd.PostedFile.FileName); string filename_bill = Path.GetFileName(fileupd1.PostedFile.FileName); string filename_test = Path.GetFileName(fileupd2.PostedFile.FileName); Stream str = fileupd.PostedFile.InputStream; Stream str1 = fileupd1.PostedFile.InputStream; Stream str2 = fileupd2.PostedFile.InputStream; BinaryReader br = new BinaryReader(str); Byte[] size = br.ReadBytes((int)str.Length); SqlCommand cmd = new SqlCommand(); cmd.Connection = con; cmd.CommandText = " insert into medicine (pres, medicine_bills, test_bills) values(@pres, @medicine_bills, @test_bills)"; cmd.Parameters.AddWithValue("@pres", fileupd.FileName); cmd.Parameters.AddWithValue("@medicine_bills", fileupd1.FileName); cmd.Parameters.AddWithValue("@test_bills", fileupd2.FileName); con.Open(); cmd.ExecuteNonQuery(); con.Close(); BindEmployeeDetails(); }} 表是... table is...CREATE TABLE [dbo].[medicine]( [s_no] [int] IDENTITY(1,1) NOT NULL, [bill_number] [int] NULL, [dt] [date] NULL, [shop_name] [varchar](88) NULL, [Ammount] [varchar](88) NULL, [medicine_bills] [varbinary](max) NULL, [test_bills] [varbinary](max) NULL, [pres] [varbinary](max) NULL, 推荐答案 可能你错误地定义了你的表。尝试将字段的数据类型从varbinary更改为varchar，因为它对于那些类型的数据是更相关的数据类型。 Probably you have defined your table incorrectly. Try changing the datatype of fields from varbinary to varchar beacause it is more relevent datatype for those kind of data.ALTER TABLE [dbo].[medicine]ALTER COLUMN [medicine_bills] VARCHAR(MAX) NULLALTER TABLE [dbo].[medicine]ALTER COLUMN [test_bills] VARCHAR(MAX) NULLALTER TABLE [dbo].[medicine]ALTER COLUMN [pres] VARCHAR(MAX) NULL 注意：如果要将文件保存到数据库中你需要将它们转换为字节数组，你可以使用现有的表结构保存它们。 希望，它有帮助：）Note: if you want to save the files in to the database then you need convert them to byte array and you can save them with the existing table structure.Hope, it helps :) 这篇关于不允许从数据类型nvarchar到varbinary（max）的隐式转换。使用CONVERT函数运行此查询。的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！ 10-09 22:10