OLEdbcommand.Prepare错误 [英] OLEdbcommand.Prepare error
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问题描述
我遇到错误:
OleDbCommand.Prepare方法要求所有参数都具有显式设置的类型.
OleDbCommand.Prepare method requires all parameters to have an explicitly set type.
在下面代码的最后一行. 我已经看到了一些事情,说您必须设置每个参数的数据类型,但是当命令生成器生成它时我该怎么做呢?
on the last line of the code below. I have seen things saying you have to set the datatype of each parameter but how can i do that when it being generated by the command builder?
我已经看到人们说他们不喜欢使用自动生成的查询,这是做我想做的事情的不好方法吗?
I have seen people say they dont like using autogenerated queries, is this a bad way to go about doing what I am trying to do?
Dim checkDock As New OleDbCommand("SELECT Instance, DocketNumber, FormID, FieldName, Occurrence, FieldValue FROM fielddata WHERE docketnumber = @dock AND formid = @formid " & _
"AND instance = @inst1")
checkDock.Connection = New OleDbConnection("Provider=" & My.Settings.Provider & ";" & "Data Source=" & My.Settings.DataSource1)
'create and execute the command to retrieve the saved data for the original instance
checkDock.Parameters.AddWithValue("@dock", dock)
checkDock.Parameters.AddWithValue("@formid", formid)
checkDock.Parameters.AddWithValue("@inst1", inst1)
Dim da As New OleDbDataAdapter(checkDock)
Dim dSet As New DataSet("copySet")
da.Fill(dSet)
'create a command builder to put the new entries in the database
Dim cb As New OleDb.OleDbCommandBuilder(da)
Dim rowList As New ArrayList()
For Each r As DataRow In dSet.Tables(0).Rows
Dim dRow As DataRow = dSet.Tables(0).NewRow
dRow.Item("Docketnumber") = dock2
dRow.Item("Formid") = formid
dRow.Item("fieldname") = r.Item("fieldname")
dRow.Item("occurrence") = r.Item("occurrence")
dRow.Item("fieldvalue") = r.Item("fieldvalue")
dRow.Item("Instance") = inst2
rowList.Add(dRow)
Next
For Each a As DataRow In rowList
dSet.Tables(0).Rows.Add(a)
Next
da.Update(dSet)
推荐答案
,您需要在此处指定参数类型.而不是这样:
you need to specify the parameter types here. Rather than this:
checkDock.Parameters.AddWithValue("@dock", dock)
checkDock.Parameters.AddWithValue("@formid", formid)
checkDock.Parameters.AddWithValue("@inst1", inst1)
使用此方法:
// replace ??? with the correct type
checkDock.Parameters.Add("@dock", OleDbType.???).Value = dock;
checkDock.Parameters.Add("@formid", OleDbType.???).Value = formid;
checkDock.Parameters.Add("@inst1", OleDbType.???).Value = inst1;
希望有帮助.
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