When inserting data from a query to a table, does the query run for each record inserted?

Question

I\'m inserting data problematically into tables. When I do this from another table, it\'s swift, only slowed very slightly if there are a lot of records. Even then, it\'s a

Answer 1

Building on pegicity's answer, my eventual code was:

Option Compare Database

Sub Concatenate(strTableToConcatenate As String, strFieldToConcatenate As String, strIDField As String)

Dim rsSource As DAO.Recordset
Dim rsDestination As DAO.Recordset
Dim qry As String
Dim strSourceTable As String
Dim i As Integer
Dim strFieldName As String
Dim strValue As String
Dim intConcatenateID As Integer
Dim intSortID As Integer

strSourceTable = strTableToConcatenate & " (Concatenate)" 'Creates a duplicate copy of the table to be concatenated and empties the original table'
DeleteTable (strSourceTable)
DoCmd.CopyObject , strSourceTable, acTable, strTableToConcatenate
qry = "DELETE FROM [" & strTableToConcatenate & "]"
CurrentDb.Execute (qry)

qry = "ALTER TABLE [" & strTableToConcatenate & "] ALTER COLUMN [" & strFieldToConcatenate & "] memo" 'Changes the DataType of the field to be concatenated to Memo, as the result may be considerably longer than the original data'
CurrentDb.Execute (qry)

i = 0
intCurrentID = 0

qry = "SELECT * FROM [" & strSourceTable & "] ORDER BY [" & strIDField & "], [" & strFieldToConcatenate & "]"
Set rsSource = CurrentDb.OpenRecordset(qry, dbOpenDynaset)
qry = "SELECT * FROM [" & strTableToConcatenate & "]"
Set rsDestination = CurrentDb.OpenRecordset(qry, dbOpenDynaset)

For Each fld In rsSource.Fields 'Finds the column number of the fields you are sorting by and concatenating from your source table.'
    strFieldName = rsSource.Fields(i).Name
    If strFieldName = strFieldToConcatenate Then
        intConcatenateID = i
    ElseIf strFieldName = strIDField Then
        intSortID = i
    End If
    i = i + 1
Next

If rsSource.recordcount <> 0 Then

    rsSource.MoveFirst
    intCurrentID = rsSource.Fields(intSortID).Value
    strConcatenateValue = ""

    While Not rsSource.EOF 'The source recordset is sorted by your designated sort field, so any duplicates of that field will be next to each other. If the row below has the same id as the row above, the sub continues to build the concatenated value. If the row changes, it adds the concatenated value to the destination record set.'

       If intCurrentID = rsSource.Fields(intSortID).Value Then

            strConcatenateValue = strConcatenateValue & "," & rsSource.Fields(intConcatenateID).Value
            rsSource.MoveNext

       Else
            rsDestination.AddNew

            i = 0

            If Len(strConcatenateValue) > 0 Then
                strConcatenateValue = Right(strConcatenateValue, Len(strConcatenateValue) - 1)
            End If

            For Each fld In rsSource.Fields
                strFieldName = rsSource.Fields(i).Name
                If strFieldName = strFieldToConcatenate Then
                     strValue = strConcatenateValue
                ElseIf strFieldName = strIDField Then
                    strValue = intCurrentID
                Else
                    strValue = rsSource.Fields(i).Value
                End If
                rsDestination.Fields(strFieldName) = "" & strValue & ""
                i = i + 1
            Next

            rsDestination.Update
            intCurrentID = rsSource.Fields(intSortID).Value
            strConcatenateValue = ""

       End If

     Wend

End If

rsSource.Close
rsDestination.Close
Set rsSource = Nothing
Set rsDestination = Nothing

End Sub