vb中如何实现两个表的连接查询?sql语句没问题,但执行不了。(有其它代码)
Dim cn As New ADODB.Connection
Dim cmd As New ADODB.Command
Dim rst As New ADODB.Recordset
cn.Mode = adModeShareDenyWrite
cn.Open "dsn=TextBook"
Set cmd.ActiveConnection = cn
rst.CursorLocation = adUseClient
cmd.CommandText = " SELECT Products.product_id, Products.product_name,Products.quantity_in_unit, Products.出版时间Supplier.company_name as scompany_name ,Products.unit_price FROM tastrade!supplier RIGHT OUTER JOIN tastrade!products ON Supplier.supplier_id = Products.supplier_id"cmd.CommandType = adCmdText
cmd.CommandType = adCmdText
rst.Open cmd, , adOpenForwardOnly, adLockReadOnly
Set rst.ActiveConnection = Nothing
If rst.RecordCount = 0 Then
MsgBox "教材科目前已无库存!", 64, "结果"
Welcome.WriteTemplate
Exit Sub
End If
With Response
.Write "<HTML>"
.Write "<BODY>"
.Write "<p align=""center""><b><font color=#2781c9 size=6>库存书目</font></b></p>"
.Write "<hr>"
.Write "<table BORDER CELLSPACING=1 CELLPADDING=7><TR>"
.Write "<tr><td>教材代码</td><td>教材名称</td><td>作者</td>"
.Write "<td>出版时间(版次)</td><td>出版社</td><td>单价</td>"
While Not rst.EOF
.Write "<TR>"
.Write "<TD>" & rst.Fields("product_id") & "</TD>"
.Write "<TD>" & rst.Fields("product_name") & "</TD>"
.Write "<TD>" & rst.Fields("quantity_in_unit") & "</TD>"
.Write "<TD>" & rst.Fields("出版时间") & "</TD>"
.Write "<TD>" & rst.Fields("scompany_name") & "</TD>"
.Write "<TD>" & rst.Fields("unit_price") & "</TD>"
.Write "</TR>"
rst.MoveNext
wend
.Write "</table>"
.Write "<hr>"
.Write "<p align=""right""><a href=""" & URLFor(Welcome) & """>返 回</a></p>"
.Write "</BODY></HTML>"
End With
Set cn = Nothing
Set cmd = Nothing
Set rst = Nothing
返回的rst中只有一个表中的字段,而另一表的字段为空,左、右、内、全联接都试过了,能返回一个表就算不错的,有的什么也回不来。