I am doing a 3 tier application to retrieve image from sql server which i stored image to binary data in sql, and the problem is i can't retrieve my image from the sql server.
here is my code in DataAccessLayer
public List<Volunteer> VolunteerTRetrieve()
{
List<Volunteer> vList = new List<Volunteer>();
byte[] volunteerProfilePicture;
string volunteerName, volunteerNRIC, volunteerAddress, volunteerEmail, volunteerContact;
string queryStr = "SELECT * FROM TVolunteer Order By VolunteerName";
SqlConnection conn = new SqlConnection(DBconnStr);
SqlCommand cmd = new SqlCommand(queryStr, conn);
conn.Open();
SqlDataReader dr = cmd.ExecuteReader();
while ((dr.Read()))
{
volunteerName = dr["VolunteerName"].ToString();
volunteerNRIC = dr["VolunteerNRIC"].ToString();
volunteerAddress = dr["VolunteerAddress"].ToString();
volunteerEmail = dr["VolunteerEmail"].ToString();
volunteerContact = dr["VolunteerContact"].ToString();
volunteerProfilePicture = (byte[])dr["VolunteerProfilePicture"];
vList.Add(new Volunteer(volunteerName, volunteerNRIC, volunteerAddress, volunteerEmail, volunteerContact, volunteerProfilePicture));
}
conn.Close();
dr.Dispose();
return vList;
}
in BusinessLogicLayer
public List<Volunteer> RetrieveAllBVolunteer()
{
Volunteer v = new Volunteer();
List<Volunteer> vList = new List<Volunteer>();
vList = v.VolunteerBRetrieve();
return vList;
}
and in PresentationLayer
List<Volunteer> allVolunteer = new List<Volunteer>();
allVolunteer = vBLL.RetrieveAllTVolunteer();
dl_tvolunteer.DataSource = allVolunteer;
dl_tvolunteer.DataBind();
I have also an image handler class
public class ShowImage : IHttpHandler
{
public void ProcessRequest(HttpContext context)
{
string connStr = System.Configuration.ConfigurationManager.ConnectionStrings["DBconnStr"].ConnectionString;
SqlConnection conn = new SqlConnection(connStr);
conn.Open();
string queryStr = "SELECT VolunteerProfilePicture FROM TVolunteer WHERE VolunteerNRIC = #NRIC";
SqlCommand cmd = new SqlCommand(queryStr, conn);
cmd.Parameters.Add("#NRIC", SqlDbType.VarChar).Value =
context.Request.QueryString["VolunteerNRIC"];
cmd.Prepare();
SqlDataReader dr = cmd.ExecuteReader();
dr.Read();
context.Response.BinaryWrite((byte[])dr["VolunteerProfilePicture"]);
}
Please help, Thankyou!
If you are returning one image you could the following
1. place a PictureBox control on the asp.net webpage
2. define the sql connections //not sure why you are using cmd.prepare
byte[] sqlImage = (byte[])cmd.ExecuteScalar();
MemoryStream memStream = new MemoryStream();
memStream.Write(sqlImage, 0, sqlImage.Length);
Bitmap bit = new Bitmap(memStream);
or if you want to do it a different way
try
{
con = new SqlConnection(constr);
cmd = new SqlCommand("select photopath,Photo from employees where employeeid=14", con);
con.Open();
dr = cmd.ExecuteReader();
while(dr.Read())
{
if (!dr.IsDBNull(1))
{
byte[] photo = (byte[])dr[1];
MemoryStream ms = new MemoryStream(photo);
pictureBox1.Image = Image.FromStream(ms);
}
}
}
catch (Exception ex)
{
dr.Close();
cmd.Dispose();
con.Close();
Response.Write(ex.Message);
}
Related
I'm having a trouble with my code.
I'm trying to have the user the ability to submit his email to subscribe to my "notify me" service, I havn't code anything lately so I a bit confused..
I'm trying to Insert, Read, and Update data in my Online SQL Server.. but nothing seems to work! I don't know why I tried everything I know I check a million times it seems good.
Plus if there is any errors my catch should show it to me but even that doesn't work :(
Take a look at this maybe your eyes will see something I don't see.
protected void btnSubmit_Click(object sender, EventArgs e)
{
string cs = ConfigurationManager.ConnectionStrings["notifyCS"].ConnectionString;
using (SqlConnection conn = new SqlConnection(cs))
{
conn.Open();
try
{
string checkEmail = "SELECT User_Email FROM tbl_users WHERE User_Email = #User_Email";
string checkSubscription = "SELECT User_Status FROM tbl_users WHERE User_Email = #User_Email";
string submitEmail = "INSERT INTO tbl_users (User_UID, User_Email, User_Status) VALUES (#User_UID, #User_Email, #User_Status)";
string submitEmail2 = "UPDATE tbl_users SET User_UID = #User_UID, User_Status = #User_Status WHERE User_Email = #User_Email";
SqlCommand emailCMD = new SqlCommand(checkEmail, conn);
SqlDataAdapter emailSDA = new SqlDataAdapter
{
SelectCommand = emailCMD
};
DataSet emailDS = new DataSet();
emailSDA.Fill(emailDS);
//if there is no email registered.
if (emailDS.Tables[0].Rows.Count == 0)
{
SqlCommand registerEmail = new SqlCommand(submitEmail, conn);
string User_UID = System.Guid.NewGuid().ToString().Replace("-", "").ToUpper();
registerEmail.Parameters.AddWithValue("#User_UID", HttpUtility.HtmlEncode(User_UID));
registerEmail.Parameters.AddWithValue("#User_Email", HttpUtility.HtmlEncode(email.Text));
registerEmail.Parameters.AddWithValue("#User_Status", HttpUtility.HtmlEncode("subscribed"));
registerEmail.ExecuteNonQuery();
registerEmail.Dispose();
conn.Close();
conn.Dispose();
email.Text = null;
}
else if (emailDS.Tables[0].Rows.Count > 0)
{
using (SqlCommand checkSub = new SqlCommand(checkSubscription, conn))
{
checkSub.Parameters.AddWithValue("#User_Email", HttpUtility.HtmlEncode(email.Text));
SqlDataReader sdr = checkSub.ExecuteReader();
if (sdr.HasRows)
{
string res = sdr["User_Status"].ToString();
if (res != "subscribed")
{
using (SqlCommand registerEmail2 = new SqlCommand(submitEmail2, conn))
{
string User_UID = System.Guid.NewGuid().ToString().Replace("-", "").ToUpper();
registerEmail2.Parameters.AddWithValue("#User_UID", HttpUtility.HtmlEncode(User_UID));
registerEmail2.Parameters.AddWithValue("#User_Email", HttpUtility.HtmlEncode(email.Text));
registerEmail2.Parameters.AddWithValue("#User_Status", HttpUtility.HtmlEncode("subscribed"));
registerEmail2.ExecuteNonQuery();
registerEmail2.Dispose();
conn.Close();
conn.Dispose();
email.Text = null;
}
}
else
{
conn.Close();
conn.Dispose();
Response.Redirect("index.aspx");
}
}
}
}
}
catch (Exception ex)
{
Response.Write(ex.Message);
}
finally
{
conn.Close();
if (conn.State != ConnectionState.Closed)
{
conn.Close();
conn.Dispose();
}
}
}
}
Try it this way:
using (SqlConnection conn = new SqlConnection(cs))
{
conn.Open();
string checkEmail = "SELECT * FROM tbl_users WHERE User_Email = #User";
SqlCommand emailCMD = new SqlCommand(checkEmail, conn);
emailCMD.Parameters.Add("#User", SqlDbType.NVarChar).Value = email.Text;
SqlDataAdapter da = new SqlDataAdapter(emailCMD);
SqlCommandBuilder daU = new SqlCommandBuilder(da);
DataTable emailRecs = new DataTable();
emailRecs.Load(emailCMD.ExecuteReader());
DataRow OneRec;
if (emailRecs.Rows.Count == 0)
{
OneRec = emailRecs.NewRow();
emailRecs.Rows.Add(OneRec);
}
else
{
// record exists
OneRec = emailRecs.Rows[0];
}
// modify reocrd
OneRec["User_UID"] = User_UID;
OneRec["User_Email"] = email.Text;
OneRec["User_Status"] = "subscribed";
email.Text = null;
da.Update(emailRecs);
}
}
I want to fetch an image from the database and show it in my react-native app.where I did go wrong?
public IActionResult DownloadFile(int id)
{
DataTable table = new DataTable();
string query = #"select image from mydb.courses where id=#id";
string sqlDataSource = _configuration.GetConnectionString("UsersAppCon");
MySqlDataReader myReader;
using (MySqlConnection mycon = new MySqlConnection(sqlDataSource))
{
mycon.Open();
using (MySqlCommand myCommand = new MySqlCommand(query, mycon))
{
myReader = myCommand.ExecuteReader();
table.Load(myReader);
var fs = new FileStream(myReader, FileMode.Open);
return File(fs, "application/octet-stream");
myReader.Close();
mycon.Close();
}
}
}
I fixed it.
[HttpGet("{id}")]
public IActionResult DownloadFile(int id)
{
string pathImage = "";
DataTable table = new DataTable();
string query = #"select image from mydb.courses where id=#id";
string sqlDataSource = _configuration.GetConnectionString("UsersAppCon");
MySqlDataReader myReader;
using (MySqlConnection mycon = new MySqlConnection(sqlDataSource))
{
mycon.Open();
using (MySqlCommand myCommand = new MySqlCommand(query, mycon))
{
myCommand.Parameters.AddWithValue("#id", id);
pathImage = (string)myCommand.ExecuteScalar();
mycon.Close();
}
}
var path = #$"{pathImage}";
var fs = new FileStream(path, FileMode.Open);
return File(fs, "image/jpeg");
}
I develop a student information system.I inser the PDF file to the database as a binary for each course.I want users to download this file.Downloading file but not displaying.Where am I doing wrong.
MvcCode
public FileResult FileDownload(Ders not)
{
byte[] byteArray = GetPdfFromDB(not.DersId);
MemoryStream pdfStream = new MemoryStream();
pdfStream.Write(byteArray, 0, byteArray.Length);
pdfStream.Position = 0;
//return new FileStreamResult(pdfStream, "application/pdf");
return File(pdfStream, "application/pdf", "DersNot.pdf");
}
private byte[] GetPdfFromDB(int id)
{
#region
byte[] bytes = { };
using (SqlConnection con = new SqlConnection(#"Server=****;Database=***;UID=***;PWD=***"))
{
con.Open();
using (SqlCommand cmd = new SqlCommand())
{
cmd.CommandText = "SELECT DersNotIcerik FROM Ders WHERE DersId=#Id";
cmd.Parameters.AddWithValue("#Id", id);
cmd.Connection = con;
using (SqlDataReader sdr = cmd.ExecuteReader())
{
if (sdr.HasRows == true)
{
sdr.Read();
bytes = (byte[])sdr["DersNotIcerik"];
}
}
con.Close();
}
}
return bytes;
#endregion
}
View
#Html.ActionLink(item2.DersNotAd, "FileDownload", new { id = item2.DersId })
I solved the problem like this.We can close the subject
public FileResult FileDownload(int id)
{
SqlConnection con = new SqlConnection(#"Server=10UR\MSSQLSERVERR;Database=UniversiteDB;UID=onur;PWD=1234");
con.Open();
SqlCommand cmd = con.CreateCommand();
cmd.CommandText = "SELECT DersNotIcerik FROM Ders WHERE DersId=#Id";
cmd.Parameters.AddWithValue("#Id", id);
byte[] binaryData = (byte[])cmd.ExecuteScalar();
return File(binaryData, "application/octet-stream", "DersNot.pdf");
}
I got two classes, one for db connection and another to get data. When I use the SqlCommand type as stored procedure it returns the data table properly, but when I change the command type to text and change the command text properly it returns a null value. Why is this happening?
Class 1
public class DB_Connection
{
public SqlConnection cnn;
public SqlCommand cmd;
public SqlDataAdapter ada;
public DB_Connection()
{
cnn = new SqlConnection("Data Source=svr01;Initial Catalog=PDFScramble;Integrated Security=True");
cnn.Open();
cmd = new SqlCommand();
cmd.CommandType = CommandType.Text;// *changed in here SP or Text*
cmd.Connection = cnn;
ada = new SqlDataAdapter();
ada.SelectCommand = cmd;
}
Class 2
public class Data : DB_Connection
{
public string DException { get; set; }
public DataTable Datatable { get; set; }
public bool GetCivicEntities()
{
try
{
cmd.CommandText = "SELECT Id, Description, StateId ,EntityTypeId FROM CivicEntities";
ada.Fill(Datatable);// *Null in here*
return true;
}
catch (Exception ex)
{
DException = ex.Message;
return false;
}
}
Your Datatable is null, because of that you have this problem. This should fix it.
cmd.CommandText = "SELECT Id, Description, StateId ,EntityTypeId FROM CivicEntities";
Datatable = new DataTable();
ada.Fill(Datatable);
return true;
There is something wrong with the class structure. Check with this
using (SqlConnection conn = new SqlConnection("connectionString"))
{
SqlCommand cmd = null;
SqlParameter prm = null;
SqlDataAdapter dad = null;
DataTable dt = new DataTable();
cmd = new SqlCommand("SPName", conn);
cmd.CommandType = CommandType.StoredProcedure;
conn.Open();
dad = new SqlDataAdapter(cmd);
dad.Fill(dt);
conn.Close();
}
using (SqlConnection conn = new SqlConnection("connectionString"))
{
SqlCommand cmd = null;
SqlParameter prm = null;
SqlDataAdapter dad = null;
DataTable dt = new DataTable();
cmd = new SqlCommand("select * from dummy",conn);
cmd.CommandType = CommandType.StoredProcedure;
conn.Open();
dad = new SqlDataAdapter(cmd);
dad.Fill(dt);
conn.Close();
}
I have the following method i am using to save an object into an SQL Server CE database. I am now stuck on how to get the record back out.
public void SaveRecord(LabRecord _labrecord)
{
try
{
conn = new SqlCeConnection(_connectionString);
conn.Open();
MemoryStream memStream = new MemoryStream();
StreamWriter sw = new StreamWriter(memStream);
sw.Write(_labrecord);
SqlCeCommand sqlCmd = new SqlCeCommand("INSERT INTO LabTransactions([TrasactionType], [CAM], [TransactionObject]) VALUES ('ResultTest', 1234, #Image)", conn);
sqlCmd.Parameters.Add("#Image", SqlDbType.Image, Int32.MaxValue);
sqlCmd.Parameters["#Image"].Value = memStream.GetBuffer();
sqlCmd.ExecuteNonQuery();
}
finally
{
conn.Close();
}
}
Update
I am looking to make another class that returns a specific record.
public LabRecord getRecord(int transactionId)
{
LabRecord returnRecord = null;
try
{
conn = new SqlCeConnection(_connectionString);
conn.Open();
//.... Get the record
}
finally
{
conn.Close();
}
return returnRecord;
}
I think the problem most likely lies in the fact that the size of the #Image parameter is being set to Int32.MaxValue
Set it instead to the length of the image byte stream:
byte[] imgBytes = memStream.GetBuffer();
sqlCmd.Parameters.Add("#Image", SqlDbType.Image, imgBytes.Length);
sqlCmd.Parameters["#Image"].Value = imgBytes;
Here's an excerpt from this example (modified for your question) of how you might go about retrieving the image:
// Get the record
SqlCeCommand cmd = new SqlCeCommand("Select [TransactionObject] From LabTransactions Where [CAM] = 1234", conn);
conn.Open();
SqlCeDataReader sdr = cmd.ExecuteReader();
byte[] imgByteData = Convert.ToByte(sdr.Item("Picture"));
Bitmap bitmap = new Bitmap(new System.IO.MemoryStream(imgByteData));