vb.net 如何将 DataGridView 的更改保存到数据库？
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How to save changes from DataGridView to the database?
提问by Pierre Minesso
I would like to save the changes made to a DataGridView into the database MS SQL CE, but i can't, the changes are not saved to the database....
我想将对 DataGridView 所做的更改保存到数据库 MS SQL CE 中，但我不能，更改未保存到数据库中....
This the code (VB.net):
这是代码（VB.net）：
Private Sub Form1_Load(ByVal sender As System.Object,
ByVal e As System.EventArgs) handles MyBase.Load
Dim con As SqlCeConnection = New SqlCeConnection(@"Data Source=C:\Users\utente\Documents\test.sdf")
Dim cmd As SqlCeCommand = New SqlCeCommand("SELECT * FROM mytable", con)
con.Open()
myDA = New SqlCeDataAdapter(cmd)
Dim builder As SqlCeCommandBuilder = New SqlCeCommandBuilder(myDA)
myDataSet = New DataSet()
myDA.Fill(myDataSet, "MyTable")
DataGridView1.DataSource = myDataSet.Tables("MyTable").DefaultView
con.Close()
con = Nothing
End Sub
Private Sub edit_rec()
Dim txt1, txt2 As String
Dim indice As Integer = DataGridView1.CurrentRow.Index
txt1 = DataGridView1(0, indice).Value.ToString '(0 is the first column of datagridview)
txt2 = DataGridView1(1, indice).Value.ToString '(1 is the second) MsgBox(txt1 + " " + txt2)
'
DataGridView1(0, indice).Value = "Pippo"
DataGridView1(1, indice).Value = "Pluto"
'
Me.Validate()
Me.myDA.Update(Me.myDataSet.Tables("MyTable"))
Me.myDataSet.AcceptChanges()
'
End Sub
Thank you for any suggestion.
谢谢你的任何建议。
回答by guyh92
You need to use myDA.Update, that will commit the changes. This is because any changes that you are making are made in the local instance of that dataset. And therefore disposed of just like any other variable.
您需要使用 myDA.Update，它将提交更改。这是因为您所做的任何更改都是在该数据集的本地实例中进行的。因此，就像任何其他变量一样被处理掉。
... I can see that in your edit_rec sub, but what is calling that - there is nothing in the code that you have posted.
...我可以在您的 edit_rec sub 中看到这一点，但这是什么意思-您发布的代码中没有任何内容。
回答by user3571272
A little late perhaps.
可能有点晚了。
In the Form load event, you open and close the connection. And furthermore, all are local variables who loose any value or data when leaving the sub
在 Form load 事件中，您打开和关闭连接。此外，所有都是局部变量，在离开 sub 时会丢失任何值或数据
Public Class Form1
Dim con As SqlCeConnection
Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
con = New SqlCeConnection(@"Data Source=C:\Users\utente\Documents\test.sdf")
Dim cmd As SqlCeCommand = New SqlCeCommand("SELECT * FROM mytable", con)
con.Open()
myDA = New SqlCeDataAdapter(cmd)
Dim builder As SqlCeCommandBuilder = New SqlCeCommandBuilder(myDA)
myDataSet = New DataSet()
myDA.Fill(myDataSet, "MyTable")
DataGridView1.DataSource = myDataSet.Tables("MyTable").DefaultView
cmd.Dispose()
End Sub
***Put the closing of connection here instead or somewhere else suitable when you don't use it anymore***
Private Sub Form1_FormClosed(sender As Object, e As System.Windows.Forms.FormClosedEventArgs) Handles Me.FormClosed
con.Close()
con = Nothing
End Sub
Private Sub edit_rec()
Dim txt1, txt2 As String
Dim indice As Integer = DataGridView1.CurrentRow.Index
txt1 = DataGridView1(0, indice).Value.ToString '(0 is the first column of datagridview)
txt2 = DataGridView1(1, indice).Value.ToString '(1 is the second) MsgBox(txt1 + " " + txt2)
'
DataGridView1(0, indice).Value = "Pippo"
DataGridView1(1, indice).Value = "Pluto"
'You code to update goes here and not in my scope of answer
End Sub
End Class
回答by Kishan
I think you want to add @ with your connection string
我认为您想在连接字符串中添加 @
SqlConnection con;
con = New SqlConnection(@"Data Source=C:\Users\utente\Documents\test.sdf");
