Blog

Northwind Challenge

Welcome to the November challenge! The challenge is to create a dashboard from the data (below). It’s a simplified version of the Northwind database.

Submit your solutions to darcy@generalBI.com or post them in our facebook group.

We will have a mini-conference to go over the solutions! The solutions will be posted here too!

Looking forward to your submission!

Balancing Bins

This interesting problem showed up in the Excel Reddit so we posed it as a problem in the General BI Facebook Group.

Given the list of items on the left, how to divide them into three groups as equally as possible by weight? It doesn’t have to be the same number of items in each group. Just the closest match for weight across the three columns. The image is from Excel but show a solution in whatever tool you think is the best.

We’ll present the solutions that were submitted in the Mini-Conference this Thursday!

After that we’ll post any solutions here.

Excel SQL

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.

City of Ottawa Service Requests

Ever wonder what Power Query can do for you? Here’s a quick demonstration of using it to load data from the City of Ottawa’s Open Data repository. Also a quick demonstration how Power Query and Power Pivot can be used to easily gain insight into the data.

One of the issues that is solved in this demo is that of inconsistent vocabulary. The data refers to the city wards differently at different times. The technique demonstrated involves making a conversion table to normalize the ward vocabulary. Then Power Pivot can make the connection using a relationship or Power Query can merge the normalized vocabulary into the main file.

Another issue being demonstrated is loading and aggregating the data directly from the Web. You can then stay abreast of city updates using a refresh function.