Casting Integer to String

[vpekulas]

I'm using the following to get the table structure:

            SQL = "SELECT column_name, data_type, character_maximum_length FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = '" & strTABLE & "'"
            Call OPEN_DB()
            Dim MyCMD As New OleDb.OleDbCommand(SQL, MyConn)
            Dim MyRead As OleDb.OleDbDataReader
            MyRead = MyCMD.ExecuteReader
            Dim iItem As New ListViewItem(), intI As Int16
            While Not MyRead.Read = False
                strVALUE(0) = MyRead.GetString(0)
                strVALUE(1) = MyRead.GetString(1)
                strVALUE(2) = MyRead.GetInt32(2).ToString
                iItem = New ListViewItem(strVALUE)
                lstColumns.Items.Add(iItem)
            End While
            MyRead.Close()
            MyConn.Close()
            MyConn.Dispose()

The problem I have is that no matter what I try I can not get the 3rd value (character_maximum_length)

strVALUE(2) = MyRead.GetInt32(2).ToString

The erro I get is: Specified cast is not valid.


And I'm sure the character_maximum_length is in Integer


"Taxes are the fees we pay for civilized society" G.W.

 

[JohnYingling]

Perhaps is is actially Int16, the OLD definition of integer.
Just for kicks, try
dim int as short
int = MyRead.GetInt16(2)
strVALUE(2) = int.toString
then

dim int as int
int = MyRead.GetInt32(2)
strVALUE(2) = int.toString

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[vpekulas]

I did just that, thinking it could be int16, eventhough the return datatype is int32, doesn't work Same error.

"Taxes are the fees we pay for civilized society" G.W.

 

[JohnYingling]

I have this code that may be useful with changes and viewed in Debug Mode.

Private Function GetSchemaTable(ByVal objConn As OleDbConnection, _
ByVal strCommand As String) _
As DataTable
Dim objDBComm As New OleDbCommand()
objDBComm.Connection = objConn
objDBComm.CommandText = strCommand
objDBComm.CommandType = CommandType.TableDirect
Return (GetRdr(objConn, strCommand, CommandBehavior.SchemaOnly).GetSchemaTable)
End Function

http://www.VBResizer.com

Forms/Controls Resizing/Tabbing

http://www.VBCompare.com

Compare Code

http://www.VBSortGen.com

Generate Sort Class in VB

http://www.Vbcompare.com/Check.Htm(1979

Check To MS)

 

[adamroof]

casting is odd, have you tryed...

Dim strValue(2) As String = Ctype(myReader.GetInt32(2), Integer)

...in my example i had a drop down list with an integer value that was a string that i had to make into an integer, otherwise i got "specified cast is invalid"

Dim tstatID As DropDownList = e.Item.Cells(6).FindControl("IncStatusDDL")
Dim getStatID As String = tstatID.SelectedItem.Value
Dim statID As Integer = Ctype(getStatID, Integer)
Dim IncidentID As Integer = CType(e.Item.Cells(2).Controls(0), TextBox).Text

 

[vpekulas]

I'm completely lost, no matter what I try I can not get it to work ... thanks for the suggestions above ... still not working.

Apparently the datatype for character_maximum_length is dbtype_I4 returned using GetDatTypeName, the GetFieldType
returns system.int32. When I try to get the value using MyRead.GetInt32(2) I get "Cast is not valid"

The error is not converting the returned value to the string I can use, but rather getting the value from the DB.

"Taxes are the fees we pay for civilized society" G.W.

 

[adamroof]

Dim strVal2 As Int32 = Ctype(myReader.GetInt32(2), Int32)
Dim strVal3 As Integer = Ctype(strVal2, Int32)
Dim strValue(2) As String = Ctype(strVal3, Integer)

pull out the value as it is first, then cast the value to string, or even integer, then to string.

Just thinking it might take a couple of castings.
Interesting to know what works eventually. Ive only a few months of experience.

 

[vpekulas]

Nope, still nothing, this fails on the first line:
Dim strVal2 As Int32 = CType(MyRead.GetInt32(2), Int32)

The reason is that even though the character_maximum_length is supposed to be an int32 datatype, it's not. I even tried to convert (cast) the character_maximum_length from the SQL string to a varchar(25) but that doesn't help either.

Is there any other way of getting the max length of give field ?


"Taxes are the fees we pay for civilized society" G.W.

 

[adamroof]

Check this out...

http://www.planet-source-code.com/vb/scripts/ShowCode.asp?txtCodeId=643&lngWId=5

Im thinking as such...

SQL = "DECLARE @Character_Maximum_Length int
SELECT column_name, data_type, character_maximum_length FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = '" & strTABLE & "'"
Call OPEN_DB()
Dim MyCMD As New OleDb.OleDbCommand(SQL, MyConn)
Dim MyRead As OleDb.OleDbDataReader
MyRead = MyCMD.ExecuteReader
Dim iItem As New ListViewItem(), intI As Int16
While Not MyRead.Read = False
strVALUE(0) = MyRead.GetString(0)
strVALUE(1) = MyRead.GetString(1)
strVALUE(2) = @CHARACTER_MAXIMUM_LENGTH.ToString
iItem = New ListViewItem(strVALUE)
lstColumns.Items.Add(iItem)
End While
MyRead.Close()
MyConn.Close()
MyConn.Dispose()

 

[vpekulas]

Nothing worked until I've used

strVALUE(2) = MyRead.GetValue(2) & ""

That's the only thing that wors Who knows why .....
Thanks guys!

"Taxes are the fees we pay for civilized society" G.W.

 

[adamroof]

??? THAT EASY ???

ohh boy. Good job.

 

[JohnYingling]

What value did you get for strValue(2) with
strVALUE(2) = MyRead.GetValue(2) & ""

That solution indicates that MyRead.GetValue(2) returned the value Nothing.

http://www.VBResizer.com

Forms/Controls Resizing/Tabbing

http://www.VBCompare.com

Compare Code

http://www.VBSortGen.com

Generate Sort Class in VB

http://www.Vbcompare.com/Check.Htm(1979

Check To MS)

 

[vpekulas]

Either null or whtever the length is as a string

"Taxes are the fees we pay for civilized society" G.W.