Category: Demo

SQL (Structured Query Language) is a useful tool for Excel (not to mention a great technology for working with data in general).

Consider the table of data below. It’s a list of 20,000 people on a sheet named “person”.

The demonstration file below retrieves unique values for the title column. Download the spreadsheet and press the SQL button to see it in action.

Option Explicit

Sub load() 'Demonstration of an SQL statement
  Dim sFile, sConnectionString, oConnection, oRecordSet, sSQL
  
  sFile = ThisWorkbook.FullName 'Create a connection string that points to the data
  sConnectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" & sFile & ";Extended Properties=""Excel 12.0;HDR=Yes;IMEX=1"";"

  Set oConnection = CreateObject("adodb.connection") 'Load an ADO connection object
  Set oRecordSet = CreateObject("adodb.recordset")   'Load an ADO recordset object

  oConnection.Open sConnectionString                 'Connect the connection to the data source
  sSQL = "SELECT DISTINCT title FROM [person$]"      'Prepare an SQL statement to retrieve the data
  oRecordSet.Open sSQL, oConnection                  'Run the SQL statement, the results go to the recordset
  
  Range("A1").CopyFromRecordset oRecordSet           'Pour the result into Excel

  oRecordSet.Close                                   'Close the recordset and connection objects
  oConnection.Close
  Set oRecordSet = Nothing                           'Make sure the objects are gone
  Set oConnection = Nothing
   
End Sub

Sub clearSheet() 'Clear the sheet
  Cells.Select
  Selection.ClearContents
  Range("A1").Select
End Sub

'Copyright Darcy Whyte, 2020
'darcy@generalBI.com

We are using ADO (ActiveX Data Objects) in order to work with SQL. This requires a few lines of code to set this up. To use this more conveniently and abstractly we can create an SQL Class to encapsulate those lines. Then the code reduces to this.

Sub LoadTitle()
  Dim s As New SQL
  s.start "SELECT DISTINCT title FROM [person$]"
  Range("A1").CopyFromRecordset s.oRS
End Sub

Now it’s much easier to leverage the convenience and power of SQL. Here are more examples.

Sub LoadTitle() 'Unique values of the title column
  Dim s As New SQL
  s.start "SELECT DISTINCT title FROM [person$]"
  Range("A1").CopyFromRecordset s.oRS
End Sub

Sub LoadGender() 'Unique values of gender
  Dim s As New SQL
  s.start "SELECT DISTINCT gender FROM [person$]"
  Range("A6").CopyFromRecordset s.oRS
End Sub

Sub LoadStateCounts() 'Counts by state ordered by count descending
  Dim s As New SQL
  s.start "SELECT state, count(*) as stateCount FROM [person$] group by state order by count(*) desc"
  Range("C1").CopyFromRecordset s.oRS
End Sub

Sub LoadKapuskasing() 'All the people in Kapuskasing
  Dim s As New SQL
  s.start "SELECT * FROM [person$] where city = 'kapuskasing'"
  Range("A15").CopyFromRecordset s.oRS
End Sub

You can also retrieve data from other Excel Workbooks or Access. This can be done just by changing the connection string. A connection string can be made for any database that supports ODBC (Open Database Connectivity).

Option Explicit

Sub goGetItLocal()
  logNote "starting local"
  Dim s As New SQL
  s.start "select top 20 * from " & s.TableRef("person") & " order by givenname"
  logNote "data loaded"
  Sheet1.Range("A1").CopyFromRecordset s.oRS
  logNote "data loaded to spreadsheet"
End Sub

Sub goGetItOtherExcel()
  logNote "starting other excel"
  Dim s As New SQL
  s.setFile "B.xlsx"
  s.start "select top 20 * from " & s.TableRef("person") & " order by givenname"
  logNote "data loaded"
  Sheet1.Range("A1").CopyFromRecordset s.oRS
  logNote "data loaded to spreadsheet"
End Sub

Sub goGetItAccess()
  logNote "starting access"
  Dim s As New SQL
  s.setFile "C.accdb"
  s.start "select top 20 * from " & s.TableRef("person") & " order by givenname"
  logNote "data loaded"
  Sheet1.Range("A1").CopyFromRecordset s.oRS
  logNote "data loaded to spreadsheet"
End Sub

If you’re interested learning SQL it’s easy and fun. Here’s a one hour video we just retrieved from google search.