📄 datarelation.aspx
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<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.OleDb" %>
<html>
<script language="VB" runat="server">
Sub readDs(Sender As Object, E As EventArgs)
Dim dv as DataView
Dim i as integer
Dim myConnection As OleDbConnection
Dim myCommand As OleDbDataAdapter
Dim ds As New DataSet
Dim ConnStr As String
Dim SQL As String
ConnStr = "Provider=SQLOLEDB; Data Source=(local); Initial Catalog=pubs;User ID=sa;"
myConnection = New OleDbConnection(ConnStr)
'Populate authors table
SQL = "select * from authors "
myCommand = New OleDbDataAdapter(SQL, myConnection)
myCommand.Fill(ds, "authors")
'Populate TitlesAuthor
SQL = "select * from titleAuthor"
myCommand = New OleDbDataAdapter(SQL, myConnection)
myCommand.Fill(ds, "titleauthor")
'Define a relation based on the au_id
'dc1 is the primary, dc2 is the secondary table
Dim dc1 As DataColumn
Dim dc2 As DataColumn
dc1 = ds.Tables("Authors").Columns("au_id")
dc2 = ds.Tables("titleauthor").Columns("au_id")
Dim dr As DataRelation
dr = New DataRelation("vRelation", dc1, dc2)
ds.Relations.Add(dr)
'Loop thru the relation
dim child() as datarow
dim r as datarow
for each r in ds.Tables("Authors").Rows
child = r.GetChildRows(ds.Relations("vRelation"))
for i = 0 to UBound(child)
Response.Write(child(i)("au_id").ToString )
next
next
end sub
</script>
<body>
<h3><font face="Verdana">DataView</font></h3>
<form runat=server>
<asp:button text="Read Relation" Onclick="readDs" runat=server/>
</form>
</body>
</html>
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