Oracle BLOB datatype to RichTextBox

问题

I got an Oracle table with a number of columns. 1 of these columns in a BLOB datatype. I got a simple query in VB.NET that is retrieving all data from this table, and populates my form. However, I'm having some problems with the BLOB column.

I have this bit of code:

 cmd.CommandText = "select * from local_it.local_email_template where name = '" & cb_EmailName.Text & "'"

    dr = cmd.ExecuteReader
    dr.Read()
    tb_Username.Text = dr.Item(1)
    tb_Password.Text = dr.Item(2)
    tb_FromName.Text = dr.Item(3)
    tb_FromEmail.Text = dr.Item(4)
    tb_Host.Text = dr.Item(5)
    n_Port.Value = dr.Item(6)
    cb_Action.Text = dr.Item(7)
    tb_Subject.Text = dr.Item(8)
    rtb_Body.Text = dr.Item(9)
    dr.Close()

But I'm getting an error on the line rtb_Body.text = dr.item(9), saying

Conversion from type 'Byte()' to type 'String' is not valid

So I tried to say rtb_Body.text = dr.item(9).tostring, but now I just get the text

System.Byte[]

in my RichRextBox.

So my question is: How do I write this bit (or my query for that matter) so I get the actual text in my RichRextBox?

Working with Visual Studio 2012, VB.NET on an Oracle g11 Database

回答1:

You can use enconding functions from System.Text namespace:

for save in blob field:

Dim blob_bytes_to_db As Byte() = System.Text.Encoding.ASCII.GetBytes(RichTextBox1.Rtf)
for load blob into richtextbox:

RichTextBox1.Rtf = System.Text.Encoding.ASCII.GetChars(blob_bytes_from_db)

Note: With RichTextBox1 .Text property can get/set clean text only. If you want to get/set formatted text with all RTF codes, use .Rtf property.

来源：https://stackoverflow.com/questions/33563778/oracle-blob-datatype-to-richtextbox

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database

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Oracle

blob