Replace SQL query parameter in a Excel power query - excel

Question

I have a workbook where I fetch data from SQL Server using fixed parameter values for a SQL query.
I want to make another sheet and have the parameter for the SQL query be taken from the cell values.
I didn't find anything on this regard.
Also I would like to refresh the data as soon as the cell values changes in the other sheet.

Answer 1

For this to work, you need to set up three different parts:
1) A parameter table in an Excel sheet
2) Changes to the advanced editor in PowerQuery
3) A macro to refresh the PQ when any cells in the parameter table are changed
1) Excel Table
You can see I included a column called param which can hold a Parameter name to help keep straight which parameter is which.
2) PQ Advanced Editor
let
ParamTable = Excel.CurrentWorkbook(){[Name="Table1"]}[Content],
Param = "'" & Text.From(ParamTable[value]{0}) & "'",
Source = Sql.Database("IP Address", "Database Name", [Query="Select * from weeks#(lf)where date >= '2018-01-01' and date < " &Param])
in
Source
Equivalent alternative: (Difference in location of variable used in SQL query.)
let
ParamTable = Excel.CurrentWorkbook(){[Name="Table1"]}[Content],
Param = "'" & Text.From(ParamTable[value]{0}) & "'",
Source = Sql.Database("IP Address", "Database Name", [Query="Select * from weeks#(lf)where date < " &Param & " and date >= '2018-01-01'"])
in
Source
Alternative Variable Type: (If dealing with numbers, the string markers ' aren't required)
let
ParamTable = Excel.CurrentWorkbook(){[Name="Table1"]}[Content],
Param = Text.From(ParamTable[value]{0}),
Source = Sql.Database("IP Address", "Database Name", [Query="Select * from weeks#(lf)where cnt < " &Param & " and date >= '2018-01-01'"])
in
Source
Explanation:
After pulling the Parameter Table into the PQ Query (ParamTable = Excel.CurrentWorkbook(){[Name="Table1"]}[Content]), the columns can be accessed by column name [value] and the rows by a zero-index number {0}. Since I was pulling in a date-value. I needed to convert it to a string value I could insert into the SQL Query -- thus the Text.From() and the appended ''s to the ends (SQL marks strings with single ' rather than the double ")
Since I named the variable Param, to use it in the string, I substituted &Param for the value which had originally been there.
2.1 Power Query's Value.NativeQuery
let
ParamTable = Excel.CurrentWorkbook(){[Name="Table1"]}[Content],
Param = ParamTable[value]{0},
Source = Value.NativeQuery(Sql.Database("IP Address", "Database Name"), "Select * from weeks where date < #dateSel and date >= '2018-01-01'",[dateSel = Param])
in
Source
Alternative Formatting:
let
ParamTable = Excel.CurrentWorkbook(){[Name="Table1"]}[Content],
Param = ParamTable[value]{0},
Source = Sql.Database("IP Address", "Database Name"),
Data = Value.NativeQuery(Source, "
Select * from weeks
where date < #dateSel and date >= '2018-01-01'
",[dateSel = Param])
in
Source
Notes:
When using Value.NativeQuery(), you can pass a date or datetime value directly in as a variable without having to include the single apostrophes.
Sometimes splitting the data retrieval into a Source step and a NativeQuery step can help with PQ's sporadic firewall issues.
3) Macro
This works for a simple check if anything in the table has changed, then runs the refresh. You will need to make sure this is placed in the correct module. Items you will need to change are:
Sheet1 is the codename of the worksheet with the parameter table.
"Table" is the name of the Parameter table
"Query - Query1" is the name of the connection to be refreshed
Note: Query1 is the name of the query. Default names for connections are usually Query - & query name
Private Sub Worksheet_Change(ByVal Target As Range)
If Not Intersect(Target, Sheet1.ListObjects("Table1").DataBodyRange) Is Nothing Then
ThisWorkbook.Connections("Query - Query1").Refresh
End If
End Sub