Question

I have a textbox and a datagrid. I am trying to enter a last name into the textbox and have that return the entire record from that last name into the datagrid from an oracle database. The code below currently returns all records in the table and is not searching by the last name.

Public Class Form1

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

    Dim myString As String
    Dim myArg As String
    Dim mysql As String
    Dim myConn As New OleDb.OleDbConnection()

    ' Create new connection
    myString = "Provider=msdaora;Data Source=XXXX;User Id=XXXX;Password=XXXX;"
    myConn.ConnectionString = myString
    myArg = TextBox1.Text
    mysql = "select * from table1 where lastname like '%'"
    Try
        myConn.Open()
    Catch ex As Exception
        MessageBox.Show(ex.Message)
    End Try

    Dim myDataadapter As New OleDb.OleDbDataAdapter(mysql, myConn)

    Dim myDs As New DataSet

    myDataadapter.Fill(myDs, "customer")

    Dim prmLName As New OleDb.OleDbParameter()
    prmLName.Direction = ParameterDirection.Input
    prmLName.Size = "10"
    prmLName.Value = TextBox1.Text


    DataGridView1.DataSource = myDs
    DataGridView1.DataMember = "customer"
End Sub
End Class

Answer 1

You didn’t pass parameter value for the lastname , so Its taking it as a null and returning all the records :

mysql = "select * from table1 where lastname like '%" 

Here you would do like :-

 mysql = "select * from table1 where lastname like '%" & txtLastName.Text & "%'"  

I will also suggest you to pass parameter by SqlCommand.Parameters Property to avoid SQL Injection.