How to get column length

[trantt]

I need to get a column length from either dataset, datasource, or a row object. What is the syntax for it?

 

Here is the old syntax (ASP):

 

recSet.Fields(iColumnIndex).DefinedSize

 

Thank you

[Robby]

Do you want the column count (or size) or the row count?

[trantt]

Column Size

[Drstein99]

This is an old post I dont see any answer and I have the same problem does anybody have a clue? because

 

esDataTable.Columns(0).MaxLength

 

returns -1 for some reason.

[Volte]

Is the first column a text field? MaxLength only returns the max lenth of text fields, and won't return the max value of number fields.

[Drstein99]

Yes. I'm working with text fields.

[trantt]

You need to get the table schema first before you can be able to get the column length:

 

1. Create your connection

2. Create you Command object(Your SQL-> this will contain the table that you go after), connection)

3. Create your OleDbDataAdapter (or SQLDataAdapter)

4. Create your DataSet

 

5. Your dataAdapter.FillSchema(Your Data Set, System.Data.SchemaType.Mapped);

 

Once you make the FillSchema call, your Maxlength shouldn't return -1 anymore.

 

Hope this will help...

[Drstein99]

Here is my code:

 

 

Public Function SelectRows(ByVal query As String) As DataTable

Dim conn As New Data.Odbc.OdbcConnection(dbConnS)

Dim adapter As New Data.Odbc.OdbcDataAdapter

Dim tDataSet As New DataSet

 

Dim tDataTable As New DataTable

 

SelectRows = Nothing

 

adapter.SelectCommand = New Data.Odbc.OdbcCommand(query, conn)

adapter.Fill(tDataSet, System.Data.SchemaType.Mapped)

tDataTable = tDataSet.Tables(0)

Dim etest As Integer

For etest = 0 To tDataTable.Columns.Count - 1

MsgBox(tDataTable.Columns(etest).MaxLength.ToString, , tDataTable.Columns(etest).ToString)

Next

 

SelectRows = tDataTable

 

 

 

conn.Dispose()

adapter.Dispose()

tDataSet.Dispose()

 

 

 

It returns -1 as maxlen for every field. I added "System.Data.SchemaType.Mapped" to the fill command and still no avail.

[Drstein99]

I also used:

 

adapter.fill(tdataset,"employee")

 

(where "employee") would be the source table for mapping. Still returns -1 on every field.

[Drstein99]

I've done a little research, looks like I may have to get into useing the

 

FillSchema

 

command. Although it's returning system errors. If any1 has any input pls help/

[Drstein99]

Nevermind guys. I fixed the problem:

 

Note to self: DO NOT have msaccess open in write mode on the table your trying to select information from another application.