How to do a database search using a textbox and a search button in visual studio VB Code - vb.net

Question

I want to type something in my txtSearchCriteria textbox and when I hit the Perform Search button it displays all the records it finds into the other textboxes I have in my form. I am using a localdb file with a dataset in Visual Studio 2012. So far I have everything working except the search button. Here is my entire code in my project.
'Import Namespaces for SQL
Imports System.Data
Imports System.Data.SqlClient
Public Class Form1 Dim objCurrencyManager As CurrencyManager
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
'Loads data into the 'CustomersDataSet.Customers' table.
Me.CustomersTableAdapter.Fill(Me.CustomersDataSet.Customers)
'Controls Record Number Movement
objCurrencyManager = CType(Me.BindingContext(CustomersBindingSource), CurrencyManager)
'Display the current record number
Position()
'Display a tool tip at the bottom of screen
lblToolStripLabel1.Text = "Ready To Compute Data"
End Sub
Private Sub btnAdd_Click(sender As Object, e As EventArgs) Handles btnAdd.Click
'Used try catch block to validate all fields to ensure proper use of form and to display error if required fields are missing user imput
Try
Me.Validate()
Me.CustomersBindingSource.EndEdit()
Me.TableAdapterManager.UpdateAll(Me.CustomersDataSet)
lblToolStripLabel1.Text = "Record Saved" 'Display that record has been saved
Catch ex As Exception
MsgBox(ex.Message)
End Try
Position()
End Sub
Private Sub btnUpdate_Click(sender As Object, e As EventArgs) Handles btnUpdate.Click
'code to update an existing record and display that redord was updated successfully
Try
Me.Validate()
Me.CustomersBindingSource.EndEdit()
Me.TableAdapterManager.UpdateAll(Me.CustomersDataSet)
lblToolStripLabel1.Text = "Record Updated" 'display record updated
Catch ex As Exception
MsgBox(ex.Message)
End Try
Position()
End Sub
Private Sub dtnDelete_Click(sender As Object, e As EventArgs) Handles dtnDelete.Click
' Removes the current record and displays the new position in the database
Me.CustomersBindingSource.RemoveCurrent()
Position()
End Sub
Private Sub btnMoveFirst_Click(sender As Object, e As EventArgs) Handles btnMoveFirst.Click
'Moves the current record to the begining of the dataset. The First Record
Me.CustomersBindingSource.MoveFirst()
Position()
End Sub
Private Sub btnMovePrevious_Click(sender As Object, e As EventArgs) Handles btnMovePrevious.Click
'moves to the previous record and displays the position
Me.CustomersBindingSource.MovePrevious()
Position()
End Sub
Private Sub btnMoveNext_Click(sender As Object, e As EventArgs) Handles btnMoveNext.Click
'Moves to the next record in the dataset
Me.CustomersBindingSource.MoveNext()
Position()
End Sub
Private Sub btnMoveLast_Click(sender As Object, e As EventArgs) Handles btnMoveLast.Click
'Moves to the last Record in the Dataset
Me.CustomersBindingSource.MoveLast()
Position()
End Sub
Private Sub Position()
'This code displays the positio of the current record the user is viewing and shows it out of the number of recors that are held in the dataset
txtRecordPosition.Text = objCurrencyManager.Position + 1 & " Of " & objCurrencyManager.Count()
End Sub
Private Sub btnNew_Click(sender As Object, e As EventArgs) Handles btnNew.Click
'Clears the form for user imput, Created a new record and adds the current date to CustomerDate field and adds the next CustomerNumber available.
Me.CustomersBindingSource.AddNew()
txtCustomerNumber.Text = Me.CustomersBindingSource.Count + 1
txtCustomerDate.Text = Date.Today.ToShortDateString
End Sub
Private Sub btnPerformSort_Click(sender As Object, e As EventArgs) Handles btnPerformSort.Click
'Code to Sort by different field within the dataset
Select Case cboField.SelectedIndex
Case 0 'CustomerNumber
CustomersBindingSource.Sort = "CustomerNumber"
Case 1 'First Name
CustomersBindingSource.Sort = "FirstName"
Case 2 'Last Name
CustomersBindingSource.Sort = "LastName"
Case 3 'City
CustomersBindingSource.Sort = "City"
Case 4 'Province
CustomersBindingSource.Sort = "Province"
End Select
btnMoveFirst_Click(Nothing, Nothing)
lblToolStripLabel1.Text = "Records Sorted"
End Sub
Private Sub btnPerformSearch_Click(sender As Object, e As EventArgs) Handles btnPerformSearch.Click
'This will take the user imput from the txtSearchCriteria textbox and return all records that have the criteria
End Sub
End Class

Answer 1

Here is a sample to query database assuming you are connecting to sql server.
Private Sub BindGrid()
Dim constr As String = ConfigurationManager.ConnectionStrings("<your connection string name>").ConnectionString
Using con As New SqlConnection(constr)
Using cmd As New SqlCommand()
cmd.CommandText = "SELECT ContactName, City, Country FROM Customers WHERE ContactName LIKE '%' + #ContactName + '%'"
cmd.Connection = con
cmd.Parameters.AddWithValue("#ContactName", txtSearch.Text.Trim())
Dim dt As New DataTable()
Using sda As New SqlDataAdapter(cmd)
sda.Fill(dt)
gvCustomers.DataSource = dt
gvCustomers.DataBind()
End Using
End Using
End Using
End Sub
To explain at first step we are declaring connection string then we are opening SqlConnection object and then we are querying the database table ContactName based on the txtSearch value inputted.Next we are filling the dataset and binding the grid.
I suggest you to read this msdn article on sql connection.