A LIKE statement does not return any data with Oracle character data type (307514)

MORE INFORMATION

Steps to Reproduce the Behavior

1. In Oracle, create a table named TestTable as follows:

   Create Table TestTable (c1 char(3));
   					

2. Insert the value 'a' into the table as follows:

   Insert into TestTable c1 values('a');
   					

3. Open Microsoft Visual Studio .NET or Visual Studio 2005.
4. Create a new Windows Application project in Visual Basic .NET.
5. Make sure that your project contains a reference to the System.Data namespace, and add a reference to this namespace if it does not.
6. Place a Command button on Form1, and change its Name property to btnTest.
7. Use the Imports statement on the System and System.Data namespaces so that you are not required to qualify declarations in those namespaces later in your code.

   Imports System
   Imports System.Data
   Imports System.Data.OleDb
   					

8. Copy and paste the following code in the code window after the "Windows Form Designer generated code" region:

   Private Sub btnTest_Click(ByVal sender As System.Object, _
   ByVal e As System.EventArgs) Handles btnTest.Click
       Dim sConnectionString As String _
           = "Provider=MSDAORA.1;User ID=scott;password=tiger;"_
             "Data Source=myOracleServer;Persist Security Info=False"
       Dim mySelectQuery As String _
           = "SELECT * FROM TestTable where c1 LIKE ?"
       Dim myConnection As New OleDbConnection(sConnectionString)
       Dim myCommand As New OleDbCommand(mySelectQuery, myConnection)
       
       'To resolve this problem, change the parameter
       'in the next line to use "%" wildcard character.
       myCommand.Parameters.Add("@p1", OleDbType.Char, 3).Value = "a"
       myConnection.Open()
       Dim myReader As OleDbDataReader = myCommand.ExecuteReader()
       Dim RecordCount as Integer
       Try
           While myReader.Read()
               RecordCount = RecordCount + 1
               MessageBox.Show(myReader.GetString(0).ToString())
           End While
           If RecordCount = 0 then
               MessageBox.Show("No data returned")
           Else
               MessageBox.Show("Number of records returned: " & RecordCount)
           End If
       Catch ex As Exception
           MessageBox.Show(ex.ToString())
       Finally
          'Always call Close when done reading.
           myReader.Close()
           myConnection.Close()
       End Try
   End Sub
   					

9. Save your project.
10. On the Debug menu, click Start, and run your project.
11. Click the button. Notice that no data is returned.
12. Change the parameter to use "%" wildcard character as follows:

    myCommand.Parameters.Add("@p1", OleDbType.Char, 3).Value = "a%"
    					

13. Run the project again. Notice that the data is returned successfully.