数据集重新调整 0 条记录，但在 access 2013 中执行时，相同的查询返回多条记录

Posted 2023-03-23

【中文标题】数据集重新调整 0 条记录，但在 access 2013 中执行时，相同的查询返回多条记录

【英文标题】：Dataset Retuns 0 records but same query returns multiple records when executed in access 2013

【发布时间】：2015-01-08 10:39:35

【问题描述】：

我将后端用作 MS Access 2013，当我执行函数时，它在消息框中返回 0，但我在 access 2013 中以 sql 模式执行相同的查询，它返回多行。问题是此函数返回 0 的原因数据集表中的行。它应该返回一些行

表格

账单(bill_id,m_id,dated,ownername,oldvalue,newvalue,units,oth,rcharges,billamount)

米（m_id,m_type,ownername,flatno,designation,qualification,department）

Private Sub frmViewStatementReport_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        Dim Billrpt As New RptBillStatement
        Billrpt.Load(Application.StartupPath & "\RptBillStatement.rpt")
        Try
            Dim qry As String
            ' I have Tried the above both queries but returns 0 rows in table(0).

            qry = "SELECT bills.ownername as Name, meters.designation as des,   meters.department as depart, bills.billAmount as amount FROM bills LEFT JOIN meters ON meters.m_id =bills.m_id  WHERE bills.dated like '*-jan-*'"

            'qry = "SELECT bt.bill_id,bt.ownername as Name, mt.designation as designation, mt.department as department,bt.billAmount as billAmount FROM bills AS bt INNER JOIN meters AS mt ON bt.m_id = mt.m_id WHERE bt.dated like '*-jan-*'"          

            Using conn = New OleDbConnection(ConString)
                Using daa As OleDbDataAdapter = New OleDbDataAdapter(qry, conn)
                    Using dss As DataSet = New DataSet
                        conn.Open()
                        daa.Fill(dss, "Bills")  
                         Dim dt As New DataTable
                        dt = ds.Tables(0)
                        Billrpt.SetDataSource(ds.Tables(0))
                        Me.CrystalReportViewer1.Refresh()
                        Me.CrystalReportViewer1.ReportSource =Billrpt 

                        MsgBox(dss.Tables(0).Rows.Count.ToString)
                        conn.Close()
                    End Using
                End Using
            End Using
        Catch ex As Exception            
            MsgBox(ex.ToString)                 
        End Try
 End Sub

【问题讨论】：

通配符几乎总是在 MS Access 之外。它仅 % 在 MS Access 查询 (DAO) 中运行

感谢 Fionnuala 为我的问题提供解决方案。

Different result from same query executed by my application and by Access 2007 query wizard的可能重复

当然我的意思是它只是 * 在 MS Access 查询 (DAO) 中运行

【参考方案1】：

通配符实际上是带有 Like 子句的 '%%' 而不是 '**'

WHERE bills.dated like '%-jan-%'"

应该可以解决你的问题。