似乎每个人都恨DateTime
值。更改格式
在我的项目,我有一个SQL SELECT
查询在数据库中找到相匹配的结果的参数值。
我的代码是:
Dim where As String = "WHERE [Supp_Code] = @scode " & _
"AND [DateFrom] = @datfrom " & _
"AND [DateTo] = @datto " & _
"AND [Comm_Code] = @ccode " & _
"AND [Customer_Code] = @custcode "
Dim sql As String = "SELECT [Comm_Code], [AqYear] FROM [Acquisition Commission] "
sql &= where & " ORDER BY [AqYear] ASC"
Dim cmd As New OleDb.OleDbCommand(sql, con)
cmd.Parameters.AddWithValue("@scode", cmbSupp.Text.Trim)
cmd.Parameters.AddWithValue("@datfrom", datFrom.Value)
cmd.Parameters.AddWithValue("@datto", datTo.Value)
cmd.Parameters.AddWithValue("@ccode", txtCommCode.Text)
cmd.Parameters.AddWithValue("@custcode", cmbCustomerCode.Text)
Dim daYear As New OleDb.OleDbDataAdapter(cmd)
Dim dsYear As New DataSet
daYear.Fill(dsYear)
代码本身没有问题。问题在于DataSet
只有0行,因为datFrom.Value
(它是DateTimePicker
控件)的DateTime
格式为'MM/dd/yyyy',但在数据库中它存储为'dd/MM/yyyy'。
什么是使用它作为一个参数之前转换其正确的数据库格式的最简单的方法?
编辑
使用下面的意见/答案,我已经适应我的代码如下:
Dim test As DateTime
Dim test2 As DateTime
test = ugDates.ActiveRow.Cells("DateFrom").Value
test = ugDates.ActiveRow.Cells("DateTo").Value
Try
Dim where As String = "WHERE [Supp_Code] = @scode " & _
"AND [DateFrom] = @datfrom " & _
"AND [DateTo] = @datto " & _
"AND [Comm_Code] = @ccode " & _
"AND [Customer_Code] = @custcode "
Dim sql As String = "SELECT DISTINCT [Comm_Code], [AqYear] FROM [Acquisition Commission] "
sql &= where & " ORDER BY [AqYear] ASC"
Dim cmd As New OleDb.OleDbCommand(sql, con)
cmd.Parameters.Add("@scode", OleDbType.VarChar).Value = cmbSupp.Text
cmd.Parameters.Add(New OleDbParameter("@datfrom", OleDbType.Date).Value = test)
cmd.Parameters.Add(New OleDbParameter("@datto", OleDbType.Date).Value = test2)
cmd.Parameters.Add("@ccode", OleDbType.VarChar).Value = txtCommCode.Text
cmd.Parameters.Add("@custcode", OleDbType.VarChar).Value = cmbCustomerCode.Text
但是,它给我的第二个参数以下错误:
的OleDbParameterCollection只接受非空OleDbParameter类型的对象,而不是布尔对象。
将datFrom.ToString(“dd/MM/yyyy”)足够吗? –
请参阅[我们是否可以停止使用AddWithValue()](http://blogs.msmvps.com/jcoehoorn/blog/2014/05/12/can-we-stop-using-addwithvalue-already/) –
我希望你的日期列使用日期列类型(而不是varchar/string)? –