如何统计读者的记录 [英] How to count record in reader

问题描述

我创建了一个程序，它会向用户发送电子邮件通知。现在，我想计算我的reader.item（vendor_name）中的记录，并显示返回的记录数。



我尝试过：

I created a program which will send email notification to the user. Now, I want to count the record inside my reader.item("vendor_name") and display how many records was returned.

What I have tried:

Dim sqlcmd As New OleDb.OleDbCommand("SELECT aca.vendor_id, aca.vendor_name, pvs.phone,aca.CHECK_STOCK_ID, " & _
"pvs.email_address, aia.invoice_num, aip.amount, aip.accounting_date, " & _
"aip.invoice_id, aip.check_id, aia.Description FROM ap_checks_all aca, ap_invoice_payments_all aip, " & _
"ap_invoices_all aia, ap.ap_supplier_sites_all pvs, ap.AP_CHECK_STOCKS_ALL acs " & _
"Where aca.check_id = aip.check_id And pvs.vendor_site_id = aca.vendor_site_id " & _
"AND aip.invoice_id = aia.invoice_id AND aca.org_id = 86 AND aca.bank_account_name = 'BPI 0011117635' " & _
"AND aca.REMIT_TO_SUPPLIER_SITE = 'OFFICE' and acs.CHECK_STOCK_ID= aca.PAYMENT_DOCUMENT_ID(+) " & _
"AND UPPER (acs.name) = 'DEBIT ADVICE' AND aca.check_date = '" & Format(dtDate.Value, "yyyy-MMM-dd") & "' order by aca.vendor_id", cn)

Dim myreader As OleDb.OleDbDataReader
myreader = sqlcmd.ExecuteReader()

myreader.Read()
Dim rowCount As Integer = 0

If myreader.HasRows Then

rowCount += 1

irec = rowCount.ToString

txtmsg.Text = "Processing: " & myreader.Item("vendor_name").ToString & "'s Payroll..."
myreader.NextResult()

dtl = "Run Date: " & Now() & vbCrLf & _
                  "Mail Notification successful." & vbCrLf & _
                   irec & " records processed." & vbCrLf


MsgBox(dtl)

推荐答案

正如我对你或你的同学说的那样：

As I said to you or your class mate:

引用：

你有没有理由不使用

Is there any reason why you don't just use

SELECT COUNT(*) FROM ...

作为您的SQL命令？然后SQL将为您计算它们，并返回匹配的行数而不浪费时间传输记录...

as your SQL command? Then SQL will count them for you, and return the number of matching rows without wasting time transfering the records...

如何统计读者的记录 [ ^ ]

你可以使用 while 循环遍历直到 myreader.Read（）返回值并在循环内生成一个count变量。

You can use a while loop to traverse till myreader.Read() return value and incriment a count variable inside the loop.

While reader.Read()
     rowCount += 1
End While

它会给您的记录数

it will give you number of records

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