MS Access Insert Into Slow for Large Recordset (VBA) - sql

Question

I have a section of code which creates a new table and then attempts to copy the record set values into the table. The only problem is this it is quite slow and access shows the loading symbol whilst it is executing this insert section below. Currently this problem is occurring inserting 500 records, but I will need to insert around 10,000 to 20,000 when I get a final data set.
I = 1
DoCmd.SetWarnings False
RecordSet1.MoveFirst
Do While Not RecordSet1.EOF = True
SQL = "INSERT INTO " & FullName & " ("
For Each field In RecordSet1.fields()
SQL = SQL & " " & Replace(field.Name, ".", "_") & ","
Next field
SQL = SQL & "ValidationCheck)"
SQL = SQL & " VALUES("
For Each field2 In RecordSet1.fields()
SQL = SQL & "'" & field2.Value & "',"
Next field2
SQL = SQL & Matches(I) & ")"
DoCmd.RunSQL (SQL)
RecordSet1.MoveNext
I = I + 1
Loop
What I want to know is, is there any way I can speed this up? Or are there better approaches?
(What I am trying to do is create a table at run time with a unique set of fields from a RecordSet and add an extra column with a Boolean value stored in Match array for each Record). The creation works fine, but the insertion code above is very slow.

Answer 1

Yes, use DAO. So much faster. This example copies to the same table, but you can easily modify it so copy between two tables:
Public Sub CopyRecords()
Dim rstSource As DAO.Recordset
Dim rstInsert As DAO.Recordset
Dim fld As DAO.Field
Dim strSQL As String
Dim lngLoop As Long
Dim lngCount As Long
strSQL = "SELECT * FROM tblStatus WHERE Location = '" & _
"DEFx" & "' Order by Total"
Set rstInsert = CurrentDb.OpenRecordset(strSQL)
Set rstSource = rstInsert.Clone
With rstSource
lngCount = .RecordCount
For lngLoop = 1 To lngCount
With rstInsert
.AddNew
For Each fld In rstSource.Fields
With fld
If .Attributes And dbAutoIncrField Then
' Skip Autonumber or GUID field.
ElseIf .Name = "Total" Then
' Insert default value.
rstInsert.Fields(.Name).Value = 0
ElseIf .Name = "PROCESSED_IND" Then
rstInsert.Fields(.Name).Value = vbNullString
Else
' Copy field content.
rstInsert.Fields(.Name).Value = .Value
End If
End With
Next
.Update
End With
.MoveNext
Next
rstInsert.Close
.Close
End With
Set rstInsert = Nothing
Set rstSource = Nothing
End Sub

Answer 2

For multiple inserts in a loop, don't use SQL INSERT statements. Instead use a DAO.Recordset with .AddNew.
See this answer: https://stackoverflow.com/a/33025620/3820271
As positive side effects, your code will become better readable and you don't have to deal with the multiple formats for different data types.
For Each field In RecordSet1.Fields
rsTarget(field.Name) = field.Value
Next field