vb.net listbox display tables names from database - database

I need to list all the tables in the list box from the database.mdb file. Not the contents of the tables just the tables name using Microsoft.Jet.OLEDB.4.0
I'm new to vb.net, please help.
this is what i have so far.. and i keep getting errors
Dim dbpath As String = System.IO.Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().CodeBase)
dbpath = New Uri(dbpath).LocalPath
TextBox1.Text = dbpath + "\database.mdb"
Dim userTables As DataTable = Nothing
Dim connection As System.Data.OleDb.OleDbConnection = New System.Data.OleDb.OleDbConnection()
connection.ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0; data source =" textbox1.text
' We only want user tables, not system tables
Dim restrictions() As String = New String(4) {}
restrictions(3) = "Table"
connection.Open()
' Get list of user tables
userTables = connection.GetSchema("Tables", restrictions)
connection.Close()
' Add list of table names to listBox
Dim i As Integer
For i = 0 To userTables.Rows.Count - 1 Step i + 1
ListBox1.Items.Add(userTables.Rows(i)(2).ToString())
Next

You can use the following code segment to display the list of tables in a .mdb file Click Here to get reference
Dim userTables As DataTable = Nothing
Dim connection As System.Data.OleDb.OleDbConnection = New System.Data.OleDb.OleDbConnection()
connection.ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;//your database path"
' We only want user tables, not system tables
Dim restrictions() As String = New String(4) {}
restrictions(3) = "Table"
connection.Open()
' Get list of user tables
userTables = connection.GetSchema("Tables", restrictions)
connection.Close()
' Add list of table names to listBox
Dim i As Integer
For i = 0 To userTables.Rows.Count - 1 Step i + 1
ListBox1.Items.Add(userTables.Rows(i)(2).ToString())
Next

seem this the right answer
Dim userTables As DataTable = Nothing
Dim connection As System.Data.OleDb.OleDbConnection = New System.Data.OleDb.OleDbConnection()
Dim source As String
source = TextDBPath.Text
connection.ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + source
Dim restrictions() As String = New String(3) {}
restrictions(3) = "Table"
connection.Open()
' Get list of user tables
userTables = connection.GetSchema("Tables", restrictions)
connection.Close()
' Add list of table names to listBox
Dim i As Integer
For i = 0 To userTables.Rows.Count - 1 Step i + 1
cbox.items.add(userTables.Rows(i)(2).ToString())
Next

Related

Fetching data from database into text boxes

I have designed a SQL Server database app in which I fetch data from database and then insert in text boxes. I use a function to fetch data in data table from database and then I populate textboxes. I have to use this coding again and again:
If Dt.Rows.Count > 0 Then
TxtCust_Id.Text = Dt.Rows(0).Item(0)
TxtCust_City.Text = Dt.Rows(0).Item(1)
TxtCust_Area.Text = Dt.Rows(0).Item(2)
Else
TxtCust_Id.Text = String.Empty
TxtCust_City.Text = String.Empty
TxtCust_Area.Text = String.Empty
End if
Text boxes names changes according to query tables. My question is. Is it possible to make a function or procedure to populate data in text boxes from datatable using loops or any other method? Thanks in advance.
Shared Function ExecuteSelectDt(ByVal SelectCommand As String) As DataTable
Cmd = New SqlClient.SqlCommand
Sda = New SqlDataAdapter
' Dt = New DataTable
Try
DBConnection() ' Database connection details
Sda = New SqlDataAdapter(SelectCommand, Con)
Dim dt2 As New DataTable
Sda.Fill(dt2)
CloseConnection()
Return dt2
Catch ex As Exception
CloseConnection()
MsgBox(ex.Message)
Return dt
End Try
End Function
Private Sub TxtCust_Name_Leave(sender As Object, e As EventArgs) Handles TxtCust_Name.Leave
SQuery = "select Cust_Id, Cust_City, Cust_Area from TBLCustommers where Cust_Name= '" & TxtCust_Name.Text & "'"
Dt = Nothing
Dt = BM_Class_Liberary.SQLSereverDB.ExecuteSelectDt(SQuery)
If Dt.Rows.Count > 0 Then
TxtCust_Id.Text = Dt.Rows(0).Item(0)
TxtCust_City.Text = Dt.Rows(0).Item(1)
TxtCust_Area.Text = Dt.Rows(0).Item(2)
Else
TxtCust_Id.Text = String.Empty
TxtCust_City.Text = String.Empty
TxtCust_Area.Text = String.Empty
End if
End Sub
'create and populate list
dim txtBoxes as new List(of TextBox)();
for each ctrl as Control in Form.Controls
if ctrl.GetType() Is GetType(TextBox) then txtBoxes.Add(ctrl)
next
' then do this when you get DataTable
dim theRow as DataRow = dt.Rows(0); ' whatever logic you have to getting needed row
for each col as DataColumn in dt.Columns
' use system.linq
txtBoxes.First(function(tb) tb.Name = col.ColumnName).Text = theRow(col.ColumnName).ToString()
next
Note, when theRow(col.ColumnName) is DBNull.Value, ToString will return string.Empty, which is fine because .Text can't have Nothing
Also, I used First because I did it with the premise that each column has text box.
Or, using the dictionary. Even better, I think
'create and populate dictionary
dim txtBoxes as new Dictionary(of string, TextBox)();
for each ctrl as Control in Form.Controls
if ctrl.GetType() Is GetType(TextBox) then txtBoxes.Add(ctrl.Name, ctrl)
next
' then do this when you get DataTable
dim theRow as DataRow = dt.Rows(0); ' whatever logic you have to getting needed row
for each col as DataColumn in dt.Columns
txtBoxes(col.ColumnName).Text = theRow(col.ColumnName).ToString()
next

Combobox Relation Table Did Not Show The Data

I've tried to add relation, to show the data on combobox and datagridview. I've tried this code below
Private Sub LoadSemester()
Me.OpenConn()
Dim dSet As New DataSet
Dim sql1 As String = "SELECT * FROM tbl_semester"
Dim comm1 As New SqlClient.SqlCommand(sql1, cnn)
Dim daSemester As SqlClient.SqlDataAdapter
Dim sql2 As String = "SELECT * FROM tbl_mk"
Dim comm2 As New SqlClient.SqlCommand(sql2, cnn)
Dim daMK As SqlClient.SqlDataAdapter
daMK = New SqlClient.SqlDataAdapter(comm2)
dSet.Clear()
daMK.Fill(dSet, "tbl_mk")
daSemester = New SqlClient.SqlDataAdapter(comm1)
dSet.Clear()
daSemester.Fill(dSet, "tbl_semester")
dSet.Relations.Add("relation", dSet.Tables("tbl_semester").Columns("id_pk"), dSet.Tables("tbl_pk").Columns("id_pk"))
With cmbSemester
.DataSource = dSet.Tables("tbl_semester")
.DisplayMember = "semester"
.ValueMember = "id_semester"
.SelectedIndex = 0
End With
'my datagridview here
End Sub
But it displayed nothing. But when I deleted the 'dSet.Relations.Add("relation", dSet.Tables("tbl_semester").Columns("id_pk"), dSet.Tables("tbl_pk").Columns("id_pk"))' the combobox showed the data.
I figured out maybe the problem is the dSet.Relation code. FYI, I am using SQLServer 2005 and VS Express 2012.

Listview - populate second column with corresponding items from database

Fist column of listview is populated from database (database column name KONTO - only values that starts with 2020-), second column of the listview should be populate from corresponding items to KONTO from same database column NAZIV into second column of the listview.
Description is in column NAZIV in databsase
I've been experimenting with this all day and didn't have any success.
Here is the code I have so far :
ListView1.View = System.Windows.Forms.View.Details
ListView1.Columns.Add("COL1", 100, HorizontalAlignment.Left) 'KONTO
ListView1.Columns.Add("COL2", 160, HorizontalAlignment.Left) 'NAZIV
Dim FilePath As String = "W:\GLAVNI\KOR14\"
Dim DBF_File As String = "MATIKGL"
Dim ColName As String = "KONTO"
'Dim naz As String
Using con As New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & FilePath & _
" ;Extended Properties=dBASE IV")
con.Open()
Using cmd As New OleDbCommand("SELECT * FROM MATIKGL ORDER BY KONTO, NAZIV", con)
Using reader As OleDbDataReader = cmd.ExecuteReader()
If reader.HasRows Then
While (reader.Read())
Me.ListView1.Items.Add(reader("KONTO"))
'LOOP BELOW SELECTS ALL ITEMS THAT STARTS WITH 2020-
For i = 0 To ListView1.Items.Count - 1
If ListView1.Items(i).ToString.Contains("2020-") Then
Else
ListView1.Items.Remove(ListView1.Items(i))
End If
Next
End While
Else
End If
End Using
End Using
con.Close()
End Using
Thanks.
UPDATE
To be more clear, here is the screen from database.
Only items starting with 2020- (1) should populate first column of listview, and second column should be populated with "2020-" description from column NAZIV (2).
Each LV Item has a collection of SubItems associated with it. The subItems show as columns in the Details view:
Dim lvi As ListViewItem ' scratch var for adding items
Dim tmp As String
Using cmd As New OleDbCommand("SELECT * FROM MATIKGL ORDER BY KONTO, NAZIV", con)
Using reader As OleDbDataReader = cmd.ExecuteReader()
If reader.HasRows Then
While (reader.Read())
' Db rdr returns Object, cast to string
tmp = reader.Item("KONTO").ToString
' no need to loop - just use the scratch vars
' only adding if it contains 2020
If tmp.Contains("2020-") Then
lvi = New ListViewItem
lvi.Text = tmp
' add the sub item
lvi.SubItems.Add(reader("NAZIV").toString)
ListView1.Items.Add(lvi)
End If
End While
End If
End Using
you can get rid of the tmp var using reader.Item("KONTO").ToString.Contains("2020")...the above is for clarity

Import records from CSV file into SQL Server 2008 R2 using VB .Net 2010

I need to import records from a comma delimited CSV file into an existing table in SQL Server R2 database using Visual Basic .Net 2010. Existing records in the table are to be deleted prior to import. I have been able to create an in-memory temporary DataTable and populate the records from CSV file using TextFieldParser. I have checked it by binding the in-memory DataTable to a DataGridView. But I am clueless in the second part i.e. how to insert records into the SQL table from the in-memory DataTable.
I have done the following:
`Dim TextFileReader As New TextFieldParser("C:\csvtosql\StockVB\VFPFiles\ExpSysusers.csv")
TextFileReader.TextFieldType = FileIO.FieldType.Delimited
TextFileReader.SetDelimiters(",")
Dim TextFileTable As DataTable = Nothing
Dim Column As DataColumn
Dim Row As DataRow
Dim UpperBound As Int32
Dim ColumnCount As Int32
Dim CurrentRow As String()
CurrentRow = TextFileReader.ReadFields() ' Ignore the header
While Not TextFileReader.EndOfData
Try
CurrentRow = TextFileReader.ReadFields()
If Not CurrentRow Is Nothing Then
''# Check if DataTable has been created
If TextFileTable Is Nothing Then
TextFileTable = New DataTable("TextFileTable")
''# Get number of columns
UpperBound = CurrentRow.GetUpperBound(0)
''# Create new DataTable
For ColumnCount = 0 To UpperBound
Column = New DataColumn()
Column.DataType = System.Type.GetType("System.String")
Column.ColumnName = "Column" & ColumnCount
Column.Caption = "Column" & ColumnCount
Column.ReadOnly = True
Column.Unique = False
TextFileTable.Columns.Add(Column)
Next
End If
Row = TextFileTable.NewRow
For ColumnCount = 0 To UpperBound
Row("Column" & ColumnCount) = CurrentRow(ColumnCount).ToString
Next
TextFileTable.Rows.Add(Row)
End If
Catch ex As Exception
MsgBox("Line " & ex.Message & "is not valid and will be skipped.")
End Try
End While
TextFileReader.Dispose()
DataGridView1.DataSource = TextFileTable
`
Can anybody please help/guide me??
I tried the following code to read the records from the DataTable and insert into the SQL Table. But it seems that only the first record is being added.
For Each TextFileTableDataRow As DataRow In TextFileTable.Rows
Dim Column0 As String = TextFileTableDataRow("Column0")
Dim Column1 As String = TextFileTableDataRow("Column1")
Dim Column2 As Int16 = TextFileTableDataRow("Column2")
Dim Column3 As Boolean = TextFileTableDataRow("Column3")
Dim strSqlQry As String = "INSERT INTO Personnel (Operator,OpPassword,SecurityLevel,Active) VALUES (#Operator,#OpPassword,,#SecurityLevel,#Active)"
Dim SqlconnectionString As String = gcconnect
Using connection As New SqlClient.SqlConnection(SqlconnectionString)
Dim cmd As New SqlClient.SqlCommand(strSqlQry, connection)
' create command objects and add parameters
With cmd.Parameters
.AddWithValue("#Operator", Column0)
.AddWithValue("#OpPassword", Column1)
.AddWithValue("#SecurityLevel", Column3)
.AddWithValue("#LoggedOn", Column7)
End With
Dim adapter As New SqlClient.SqlDataAdapter()
adapter.InsertCommand = cmd
'--Update the original SQL table from the datatable
Dim iRowsInserted As Int32 = adapter.Update(TextFileTable)
End Using
Next
I am getting the following error:
"Violation of PRIMARY KEY Constraint 'PK_Personnel'. Cannot insert duplicate key in object 'dbo.Personnel'."

error deleting from database

I have a SQL Server Compact database created through VS 2010 (Local Database File option).
On form load (CategoryForm) I load the values from the database into the DataGridView1. I also add an extra ButtonColumn programmatically that I use for the Delete part.
The problem is this:
On initial form load, the first time I press delete on any row, it works. If i press it again it does not work.
The second time i click the button, the printed text I get on my Msgbox, is the Text of button! (delete) (screenshot included) p.s As mentionted below, when I comment-out the extra stuff, I get the correct values returned.
What I tried:
Commented out everything SQL-related, left only the part where I get the RowIndex and the value at the specific cell at that index. I print them both on MsgBox. The values I get are correct. For example, 0 index and value test for first row with text test.
Below is my progress as well as screenshots:
CellContentClick method:
Private Sub DataGridView1_CellContectClick(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) Handles DataGridView1.CellContentClick
Dim i As String
'If e.ColumnIndex = 1 Then
'If e.RowIndex >= 0 And e.RowIndex <= DataGridView1.Rows.Count - 1 Then
i = DataGridView1.Rows(e.RowIndex).Cells(0).Value.ToString
MsgBox(e.RowIndex)
MsgBox(i)
SQLStringDelete = "DELETE FROM Category WHERE categoryname = '" & i & "'"
SQLConn.ConnectionString = ConnString 'Set the Connection String
SQLConn.Open() 'Open the connection
SQLCmd.Connection = SQLConn 'Sets the Connection to use with the SQL Command
SQLCmd.CommandText = SQLStringDelete 'Sets the SQL String
SQLCmd.ExecuteNonQuery() 'Executes SQL Command
'Create Adapter
Dim DataAdapter As SqlCeDataAdapter = New SqlCeDataAdapter("SELECT categoryname FROM Category", SQLConn)
'Create DataSet
Dim Dataset As New DataSet
'fill the datset
DataAdapter.Fill(Dataset)
'attach dataset to the datagrid
With DataGridView1
.DataSource = Dataset.Tables(0)
.Columns(0).HeaderText = ""
.Columns(0).AutoSizeMode = DataGridViewAutoSizeColumnMode.Fill
End With
DataAdapter = Nothing
Dataset = Nothing
SQLConn.Close() 'Close the connection
End Sub
Form_Load method:
Private Sub CategoryForm_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
SQLConn.ConnectionString = ConnString 'Set the Connection String
SQLConn.Open() 'Open the connection
'Create Adapter
Dim DataAdapter As SqlCeDataAdapter = New SqlCeDataAdapter("SELECT categoryname FROM Category", SQLConn)
'Create DataSet
Dim Dataset As New DataSet
'fill the datset
DataAdapter.Fill(Dataset)
'attach dataset to the datagrid
With DataGridView1
.DataSource = Dataset.Tables(0)
.Columns(0).HeaderText = ""
.Columns(0).AutoSizeMode = DataGridViewAutoSizeColumnMode.Fill
End With
DataAdapter = Nothing
Dataset = Nothing
SQLConn.Close()
With buttonColumn
.Name = "DeleteButtonColumn"
.HeaderText = ""
.Text = "Delete"
.UseColumnTextForButtonValue = True
.AutoSizeMode = DataGridViewAutoSizeColumnMode.Fill
.Width = 50
End With
If DataGridView1.Columns.Count = 1 Then
DataGridView1.Columns.Add(buttonColumn)
End If
End Sub
Screenshots:
Turns out that the columns where autoregenerating causing column re-arrangement on each the second click. Just set DataGridView1.AutoGenerateColumns = false in both the form load and event and it works.

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