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hello again
thanks for promt rep.
well to be very honest I have just started sql so i am not expert but as you said I will try to change logic and let you know
what I understand according to you that I need to open connection when form load and but do I need to close it or not but upto now what i have learnt i have to close the connection but i will see how it goes
is it possible to help me with this logic that where to start i dont want answer i will try it
waiting for your kind rep.
have a nice time
thanks
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No problem,
Perhaps the easiest way is to make the connection static so that every time you connect to the database, you get the same connection. Something like (may contain errors):
Private Function GetDBConnection()
Static SqlConn = Nothing
If SqlConn Is Nothing Then
' Compose the database file name.
' Modify this if the database is somewhere else.
Dim DBname As String = Application.StartupPath()
DBname = DBname.Substring(0, DBname.LastIndexOf("\bin"))
DBname = DBname & "\Images.mdf"
' Compose the connect string.
Dim connect_string As String = "Data Source=.\SQLEXPRESS;AttachDbFilename=" & _
DBname & ";Integrated Security=True;User Instance=True"
' Open a database connection.
SqlConn = New Data.SqlClient.SqlConnection(connect_string)
SqlConn.Open()
End If
' Return the connection.
Return SqlConn
End Function
And when using this, don't close and don't dispose the connection, so comment the lines conImage.Close() and conImage.Dispose() in btnDelete_Click and LoadImages and btnSave_Click
The idea is to test that you are using the same database all the time. If this doesn't help then we change back to the original logic and try something else.
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Hello sir
thanks for promt rep.
yes i have change the logic the way you said but still it's same problem i mean i can save or delete image from sql database but i have to close application to see the changes
and one more thing i would like to tell you that i have created another application without image but it works fine if i add or delete first name and last name it shows the changes same time and i have used same method with this application but i am not sure but i sow one difference in it
that project has one table with three columns ID, FirstName, LastName
and this is button event to change enable = false
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
Button2.Enabled = False
Button3.Enabled = False : Button4.Enabled = False : Button5.Enabled = False
Button1.Enabled = True
TextBox1.Enabled = True : TextBox2.Enabled = True
TextBox1.BackColor = Color.Aquamarine : TextBox2.BackColor = Color.Aquamarine
Try
Me.StudentBindingSource.EndEdit()
Me.StudentBindingSource.AddNew()
Catch ex As Exception
MsgBox(ex.Message)
End Try
End Sub
but with this there is only one difference
Me.StudentBindingSource.EndEdit()
Me.StudentBindingSource.AddNew()
so do you think this is the issue
waiting for your kind rep.
have a nice time
thanks again
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If you have corresponding BeginInit somewhere, you should call EndInit. Trying that is a good idea.
Also one possibility is that even if you delete the image from database, it isn't correctly refreshed in the dataset (dsImage). However you do call Clear-method so it should work.
If calling EndInit doesn't help, can you re-create the dataset (set dsImage to Nothing and create a new dsImage) and fill it after that.
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hello again
as you said that to refresh dsimage so for example if there is 4 images in database and if i delete image no 3 so after deleting image it's refreshing dataset because in picture box it shows first image but still you can go forward or backword up to image 4 but when i close application and rerun it then it shows 3 images in database so that means it refreshing dataset properly
and there is no corresponding in begininit at all so i think i dont need to endinit
so we have only last option so i think i will try tomorrow
but any way i learn lot from you i realy appriciate that
thanks a lot
if i need any help i will contact you tomorrow
good night
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You're welcome.
I'll go and have some sleep also... 
One thing you can try tomorrow is to add AcceptChanges()- call to dataset after deletion or fill. In case that the record is deleted but changes are still pending
MIka
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Hello sir
good morning
how are you
I have tried every thing but still it's same problem so now I don't know what to do
I have also tried AcceptChanges() but still it's same
waiting for your kind rep.
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I couldn't be bothered to read all the posts, but if the data is actually being deleted in the database (check from Management Studio) then you need to refresh your dataset and rebind it to your control.
Hope this helps
Bob
Ashfield Consultants Ltd
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hello sir
could you please guide me how to do this because i have just started sql so i dont know much about it i mean i dont want code but just want to know where to start
waiging for your kind rep.
have a nice day
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Its not in sql, its in your code.
I assume yuo load data from the database into a dataset and then bind the datatable(s) within the dataset to controls. When you add or delete data you need to probably (depending on how you update your database) refresh your dataset and/or rebind the datatable(s) to the controls.
Bob
Ashfield Consultants Ltd
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hello again
this is the code for add image
btnSave.Enabled = False
'get sql connection
Dim ImageAdd As Integer
Try
conImage = GetDBConnection()
dsImage.BeginInit()
Dim sSQL As String = "INSERT INTO Images (Pic,Title, IType, Height, Width) VALUES(" & _
"@pic, @title, @itype, @iheight, @iwidth)"
commImage = New Data.SqlClient.SqlCommand(sSQL, conImage)
Call GetImage()
ImageAdd = commImage.ExecuteNonQuery()
Me.daImage.Update(Me.dsImage, "Images")
dsImage.AcceptChanges()
MessageBox.Show(ImageAdd.ToString & " Image successfuly saved in database", "Image Load")
dsImage.EndInit()
Catch ex As Exception
MsgBox(ex.Message)
End Try
commImage.Dispose()
' commImage = Nothing
conImage.Close()
conImage.Dispose()
Call LoadImages()
End Sub
and when ever i add or delete image it refresh the the dataset i mean if ther is 3 images in database and if i want to delete image no. 3 after deleting image 3 it shows image no. 1 in picture that means it's reloading image that is what i am thinking
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Hi again,
Few additional questions
- about the binding. Have you bound the dsImage dataset to a BindingSource and again a picture box to that BindingSource?
- in LoadImages sub, what is the difference between ImagesTableAdapter and daImage?
- in INSERT statement, you don't specify a value for ImageID-column, but that column is used in DELETE statement. How the ImageID get's it's value
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hello again
how are you
thanks for your rep.
yes i have dound picturebox to binding source , and i am trying so many things so i add imagestable adapter but daImage is i have drag and drop on form and went through adapter wizard
and when i created Image table i have set primary key and identity specification set to yes so every time when i add new image to database it increment 1 by it self
and in delete statement i have find record to delete it so it gets the ImageID from textbox
all this is works fine but you know the problem
so now i have no idea what to do
waiting for your kind rep.
and thanks again
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Hmm, let's try to simplify this. Can you create a button and in that button call this sub (it may contain compilation errors since I wrote it in notepad). Let's see what you get with this:
Private Sub TestMethod()
Dim imageCount As Integer = dsImage.Images.Rows.Count
MsgBox("Original image count in dataset: " & CStr(imageCount))
conImage = GetDBConnection()
commImage = New Data.SqlClient.SqlCommand("DELETE FROM Images WHERE ImageID = " & txtImageFile.Text, conImage)
If commImage.ExecuteNonQuery() <> 1 Then
MsgBox("Delete failed", MsgBoxStyle.Information)
End If
dsImage.Images.Clear()
dsImage.Images.AcceptChanges()
If dsImage.Images.Rows.Count <> 0 Then
MsgBox("Datatable not empty", MsgBoxStyle.Information)
End If
Me.ImagesTableAdapter.ClearBeforeFill = True
Me.ImagesTableAdapter.Fill(Me.dsImage.Images)
If (imagecount - 1 <> dsImage.Images.Rows.Count) Then
MsgBox("Delete not done, rows in datatable: " & CStr(dsImage.Images.Rows.Count), MsgBoxStyle.Information)
End If
End Sub
What do you get as result (information in messageboxes)?
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hello again
sorry for late
i have test this and result are as bellow
WITH 0 DATA COUNT
FIRST MESSAGEBOX
1- Original Count in Database = 0
2- Error because there is no row in database so it shows error
because of this
If commImage.ExecuteNonQuery() <> 1 Then
MsgBox("Delete failed", MsgBoxStyle.Information)
End If
after that i close application and rerun it and add one image in database
so
FIRST MSGBOX
1- Original Count in DB = 1
SECOND MSGBOX
2- Delete failed
THIRD MSGBOX
3- Delete not done, Rows in datatable = 1
thanks again
waiting for your rep.
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No problem...
So the problem in this case was that there wasn't a row to delete matching the condition. Try to change the delete statement:
commImage = New Data.SqlClient.SqlCommand("DELETE FROM Images WHERE ImageID = (SELECT MAX(ImageID) FROM Images)", conImage)
This should delete the last image in images. Any difference?
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hello again
ok
with empty DB
1 msgbox
Original image count = 0
2 msgbox
delete failed
3 msgbox
Delete not done, rows in BD =0
and without closing application I add one image with original method and it shows msgbox that 1 image is saved, and then without closing application i click button to use your method still it shows that
first msgbox= original image count = 0
and in second = Delete not done row in datatable=0,
and when i click button second time without closing application
so first msgbox is original image count =0
second msgbox is delete failed
therd msgbox is row i datatable=0
so that means image has been saved in database and deleted when i click button to use your method and when i click button second so result was different
and then add one image and rerun the application so it show one image in database and i can see the image in picturebox as well now i click button for your method
so msgbox 1 Original Image count =1
msgbox2 = delete not done, row in datatable = 1
now i have click button second time without closing application so
msgbox 1 Original Image count =1
msgbox 2 Delete Failed
msgbox 3 delete not done, row in datatable = 1
so this is some thing else
i think we are going to the right direction
thanks
waiting for your kind rep.
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This is confusing... I thought that now the delete operation would have deleted 1 row.
I think I must get some sleep but in the mean time if you could test this variation with one picture in database (this should delete ALL pictures):
commImage = New Data.SqlClient.SqlCommand("DELETE FROM Images)", conImage)
...
If (dsImage.Images.Rows.Count > 0) Then
MsgBox("Delete not done, rows in datatable: " & CStr(dsImage.Images.Rows.Count), MsgBoxStyle.Information)
End If
I'll get back to this sometime tomorrow afternoon so don't hurry with this. If I'm reading the clock correctly it's past 10pm at your timezone so you could use some rest too.
Mika
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Hello again
yes you are right it's 10.30 pm now so better to rest and get back to work tomorrow but thank you very much for your help
take care
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hello again
yes i have tried new quary but still it's not working
waiting for your kind rep.
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Hi again,
What was the output from these (rowcount)?
MsgBox("Original image count in dataset: " & CStr(imageCount))
...
If (dsImage.Images.Rows.Count > 0) Then
MsgBox("Delete not done, rows in datatable: " & CStr(dsImage.Images.Rows.Count), MsgBoxStyle.Information)
End If
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hello sir
how are you
in messagebox
1st
original image count = 2
2nd msgbox
delete not done, rows in datatable = 2
and when i click ok it shows SqlException was unhandled
"Incorrect syntax near '*'
wanting for your kind rep.
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Where is that SqlException coming from? After the "Delete not done..." message box there should be no code to execute (only End If).
Another thing, the dataset is defined in the project, am I correct? Could you post the part that selects the images or do you create the SELECT statement?
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hello again
the code which exacute is as bellow
Dim imageCount As Integer = dsImage.Images.Rows.Count
MsgBox("Original image count in dataset: " & CStr(imageCount))
conImage = GetDBConnection()
commImage = New Data.SqlClient.SqlCommand("DELETE * FROM Images)", conImage)
If (dsImage.Images.Rows.Count > 0) Then
MsgBox("Delete not done, rows in datatable: " & CStr(dsImage.Images.Rows.Count), _
MsgBoxStyle.Information)
End If
and the code where error shows
If commImage.ExecuteNonQuery() <> 1 Then (this is the line)
MsgBox("Delete failed", MsgBoxStyle.Information)
End If
this is the part to get image
Private Sub GetImage()
Dim fs As FileStream = New FileStream(mImageFilePath.ToString(), FileMode.Open)
Dim img As Byte() = New Byte(fs.Length) {}
fs.Read(img, 0, fs.Length)
fs.Close()
mImageFile = Image.FromFile(mImageFilePath.ToString())
Dim imgHeight As Integer = picImage.Height 'mImageFile.Height
Dim imgWidth As Integer = picImage.Width 'mImageFile.Width
Dim imgLength As Integer = mImageFile.PropertyItems.Length
Dim imgType As String = Path.GetExtension(mImageFilePath)
mImageFile = Nothing
' image content
Dim pic As SqlParameter = New SqlParameter("@pic", SqlDbType.Image)
pic.Value = img
commImage.Parameters.Add(pic)
' title
Dim title As SqlParameter = New SqlParameter("@title", System.Data.SqlDbType.VarChar, 50)
title.Value = txtTitle.Text.ToString()
commImage.Parameters.Add(title)
' type
Dim itype As SqlParameter = New SqlParameter("@itype", System.Data.SqlDbType.Char, 4)
itype.Value = imgType.ToString()
commImage.Parameters.Add(itype)
' height
Dim iheight As SqlParameter = New SqlParameter("@iheight", System.Data.SqlDbType.Int)
iheight.Value = imgHeight
commImage.Parameters.Add(iheight)
' width
Dim iwidth As SqlParameter = New SqlParameter("@iwidth", System.Data.SqlDbType.Int)
iwidth.Value = imgWidth
commImage.Parameters.Add(iwidth)
End Sub
this is select statment
Private Sub btnSave_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSave.Click
btnSave.Enabled = False
'get sql connection
Dim ImageAdd As Integer
Try
conImage = GetDBConnection()
Dim sSQL As String = "INSERT INTO Images (Pic,Title, IType, Height, Width) VALUES(" & _
"@pic, @title, @itype, @iheight, @iwidth)"
commImage = New Data.SqlClient.SqlCommand(sSQL, conImage)
Call GetImage()
ImageAdd = commImage.ExecuteNonQuery()
'Me.daImage.Update(Me.dsImage, "Images")
dsImage.AcceptChanges()
Me.ImagesTableAdapter.ClearBeforeFill = True
Me.ImagesTableAdapter.Fill(Me.dsImage.Images)
MessageBox.Show(ImageAdd.ToString & " Image successfuly saved in database", _
"Image Load")
Catch ex As Exception
MsgBox(ex.Message)
End Try
commImage.Dispose()
commImage = Nothing
conImage.Close()
conImage.Dispose()
Call LoadImages()
End Sub
and yes I drag and drop data adaptor and then generate dataset
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Ok,
First change the following
commImage = New Data.SqlClient.SqlCommand("DELETE * FROM Images)", conImage)
to
commImage = New Data.SqlClient.SqlCommand("DELETE FROM Images)", conImage)
If you could then rerun the test where you had two images, what is the output now?
The deletion wasn't done, because of the syntax error in SQL statement, so we don't know if the deletion works or not
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