How to populate datagridview with dataset from select query? - vb.net

Question

I'm making a search bar using SELECT query and I want to transfer the results to a DataGridView. But I always get an empty DataGridView.
Nothing is wrong with the query, I already tried to input it manually in access. What am I doing wrong in the code? Here it is:
Using conn = New OleDbConnection(connstring)
Try
Dim Sql As String = "SELECT * FROM Products WHERE [Product Name] LIKE '" & txtSearchProduct.Text & "*'"
Dim da As New OleDbDataAdapter(Sql, conn)
Dim ds As New DataSet
da.Fill(ds)
DataGridView2.DataSource = ds.Tables(0)
Catch ex As Exception
MsgBox(ex.ToString, MsgBoxStyle.OkOnly Or MsgBoxStyle.Exclamation, "Error")
End Try
End Using

Answer 1

The issue is as I stated in the comment. ADO.Net uses the % for the like to maintain consistency with most major Sql engines. But I would like to point out that your query is unsafe and subject to SQL injection so I have included an example of your code using a parameter to pass user input to the command.
Also note that the OleDbDataAdapter can be declared in a Using statement the same way you did with the OleDbConnection Note that you may however have to widen the scope of the dataset (ds) if you plan on doing other things with it.
Using conn As OleDbConnection = New OleDbConnection(connstring)
Try
Dim Sql As String = "SELECT * FROM Products WHERE [Product Name] LIKE #Product"
Using da As OleDbDataAdapter = New OleDbDataAdapter(Sql, conn)
da.SelectCommand.Parameters.Add("#Product", OleDbType.Varchar).Value = txtSearchProduct.Text & "%"
Dim ds As New DataSet
da.Fill(ds)
DataGridView2.DataSource = ds.Tables(0)
End Using
Catch ex As Exception
MsgBox(ex.ToString, MsgBoxStyle.OkOnly Or MsgBoxStyle.Exclamation, "Error")
End Try
End Using

Answer 2

Like Charles has mentioned its always better to use parameters. My answer is a bit different whereas it uses a reader and not an adapter, and a datatable and not an entire dataset. An adapter should only be used if you intend to write back to the table, or typical scenarios include binding procedures. A DataSet is typically used when you have multiple tables and have a need to relate them. Also note, you most likely want a preceding % in your parameter if you want to match the string regardless of the position in the search column.
Try
Using conn = New OleDbConnection("YourConnString")
conn.Open()
Dim Cmd As New OleDbCommand("SELECT * FROM Products WHERE [Product Name] LIKE #Product", conn)
Cmd.Parameters.AddWithValue("#Product", "'%" & txtSearchProduct.Text & "%'")
Dim ProductsRDR As OleDbDataReader = Cmd.ExecuteReader
Dim DTable As New DataTable With {.TableName = "Products"}
DTable.Load(ProductsRDR)
DataGridView1.DataSource = DTable
conn.Close()
End Using
Catch ex As Exception
MsgBox(ex.ToString, MsgBoxStyle.OkOnly Or MsgBoxStyle.Exclamation, "Error")
End Try

Answer 3

All you have to do is replacing the * sign with % in your Sql string, just like this:
This is your wrong Sql string:
Dim Sql As String = "SELECT * FROM Products WHERE [Product Name] LIKE '" & txtSearchProduct.Text & "*'"
Change it to this:
Dim Sql As String = "SELECT * FROM Products WHERE [Product Name] LIKE '" & txtSearchProduct.Text & "%'"

Answer 4

This should cover most of the common scenarios out there.
Imports System.Data.SqlClient
Public Class Form1
Dim sCommand As SqlCommand
Dim sAdapter As SqlDataAdapter
Dim sBuilder As SqlCommandBuilder
Dim sDs As DataSet
Dim sTable As DataTable
Private Sub load_btn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles load_btn.Click
Dim connectionString As String = "Data Source=.;Initial Catalog=pubs;Integrated Security=True"
Dim sql As String = "SELECT * FROM Stores"
Dim connection As New SqlConnection(connectionString)
connection.Open()
sCommand = New SqlCommand(sql, connection)
sAdapter = New SqlDataAdapter(sCommand)
sBuilder = New SqlCommandBuilder(sAdapter)
sDs = New DataSet()
sAdapter.Fill(sDs, "Stores")
sTable = sDs.Tables("Stores")
connection.Close()
DataGridView1.DataSource = sDs.Tables("Stores")
DataGridView1.ReadOnly = True
save_btn.Enabled = False
DataGridView1.SelectionMode = DataGridViewSelectionMode.FullRowSelect
End Sub
Private Sub new_btn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles new_btn.Click
DataGridView1.[ReadOnly] = False
save_btn.Enabled = True
new_btn.Enabled = False
delete_btn.Enabled = False
End Sub
Private Sub delete_btn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles delete_btn.Click
If MessageBox.Show("Do you want to delete this row ?", "Delete", MessageBoxButtons.YesNo) = DialogResult.Yes Then
DataGridView1.Rows.RemoveAt(DataGridView1.SelectedRows(0).Index)
sAdapter.Update(sTable)
End If
End Sub
Private Sub save_btn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles save_btn.Click
sAdapter.Update(sTable)
DataGridView1.[ReadOnly] = True
save_btn.Enabled = False
new_btn.Enabled = True
delete_btn.Enabled = True
End Sub
End Class