need join help

  • Thread starter Thread starter cj
  • Start date Start date
C

cj

My code below gives me "SQL: Column 'BTN' is not found."

It will work if I use an inner join or just join but those two joins
don't return all the rows. BTN has 5 rows, but arcust01 has only has
matching records for 2 of them. I need the other 3 returned with nulls
in the fields from arcust01.

How can I do this?



Imports System.Data.OleDb

Public Class Form1
Dim myOleDbConnection As OleDbConnection
Dim myOleDbCommand As OleDbCommand
Dim myOleDbDataAdapter As OleDbDataAdapter

Dim dt As New DataTable

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button1.Click
myOleDbConnection = New
OleDbConnection("Provider=vfpoledb.1;Data Source=c:\;Collating
Sequence=general")
myOleDbCommand = New OleDbCommand
myOleDbDataAdapter = New OleDbDataAdapter

Dim fields As String = "select btn.btn, arcust01.lastpay,
arcust01.balance "
Dim from As String = "from btn outer join f:\chris\arcust01
arcust01 on btn.btn = arcust01.custno"

myOleDbCommand.CommandText = fields & from
'myOleDbCommand.CommandText = "select btn.btn from btn"
myOleDbCommand.Connection = myOleDbConnection

myOleDbDataAdapter.SelectCommand = myOleDbCommand

myOleDbDataAdapter.Fill(dt)

DataGridView1.DataSource = dt
MessageBox.Show("done!")
End Sub

End Class
 
Hi Chris,

Based on my understanding, you have two database tables named 'BTN' and
'Arcust01'. The table 'BTN' has 5 rows in it and there're 2 rows in the
table 'Arcust01' matching 2 of the 5 rows in the table 'BTN'. What you want
is to query both two tables and return all the 5 rows in the table 'BTN'
among which the 3 rows not being matched returned with nulls in the fields
from the table 'Arcust01'. If I'm off base, please feel free to let me know.

You should use left outer join to get what you want. The following is a
sample:

Dim sQry As String = "select btn.btn, arcust01.lastpay, arcust01.balance
from btn left outer join f:\chris\arcust01 arcust01 on btn.btn =
arcust01.custno"

myOleDbCommand.CommandText = sQry

Hope this helps.
If you have any question, please feel free to let me know.

Sincerely,
Linda Liu
Microsoft Online Community Support

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