title: How to fix runtime error '3048' "Cannot open any more databases."
body: <p>I have a form with a button that calls and filters a couple of union queries with about 40 SELECT queries total in between them. It then displays the data in a report. Each SELECT query in the Union query collects records from multiple unique tables in the database. I recently had to add a couple more SELECT queries into the union query to grab records from new tables which is when I got the runtime error. It was opening the report fine before I added these SELECT queries so im under the assumption is there are too many SELECT queries in the UNION query. To resolve this issue, do I simply not use a UNION query and find an alternative way to combine records? or is it something in the VBA code that needs adjustment?
  Here is my code</p>
  
  <pre><code>Private Sub Command189_Click()
  DoCmd.SetWarnings False
  DoCmd.Close acReport, "Operator Daily Review"
  
  Dim db As DAO.Database
  Dim qdf As DAO.QueryDef
  Dim varItem As Variant
  Dim strCriteria As String
  Dim strSQL As String
  Set db = CurrentDb()
  Set qdf = db.QueryDefs("Productivity_WeeklyFinal")
  Set qdf2 = db.QueryDefs("qFiller_Names")
  
  
     strSQL = "SELECT Info_ME_Employees.ID, gs_1_week_finalUnion.SampleID,
     gs_1_week_finalUnion.Operator, Format$([TestDate],'m/dd/yyyy') AS Test_Date,
     gs_1_week_finalUnion.Test FROM Info_ME_Employees INNER JOIN gs_1_week_finalUnion ON
     Info_ME_Employees.Full_Name = gs_1_week_finalUnion.Operator" &amp; _
     " WHERE Info_ME_Employees.ID IN (4,5,6,7)AND gs_1_week_finalUnion.TestDate Between (Date()-7-
      Weekday(Date(),2)) And (Date()-Weekday(Date(),2)-1) " &amp; _
          " ORDER BY gs_1_week_finalUnion.Operator"
     strSQL2 = "SELECT Info_ME_Employees.ID, Info_ME_Employees.Full_Name FROM Info_ME_Employees" &amp; _
     " WHERE Info_ME_Employees.ID IN (4,5,6,7)"
  
      qdf.SQL = strSQL
      qdf2.SQL = strSQL2
  
      DoCmd.OpenReport "Operator Daily Review", acViewReport
  
     Set db = Nothing
     Set qdf = Nothing
  End Sub
  </code></pre>