Dynamically build a SQL Insert statement based on results from a DataView - sql-server

Question

I have a legacy data logging industrial app that I'm writing a new interface for. The program lets you select points on devices, save those to a profile, then select devices to apply that profile for. When you apply the profile it create a table for each device using the devices unique ID as the table name and creates columns for each point of data you will be logging using the unique point ID. For example I select 3 points of information to datalog and it saves those three as a Profile (into it's own table) and then the point into the Points table tagged with that Profile:
PointID PointName ProfileID
33 Temp23 1
34 Hum14 1
35 Stat 1
I then select a couple devices and apply that profile which saves to the Device table:
DeviceID DeviceName ProfileID
5 NWUnit 1
6 NEUnit 1
After it saves the devices it creates the table per device such as:
Table Name: DEV5
Column 1: PNT1 - Float
Column 2: PNT2 - Float
Column 3: PNT3 - Bit
As you can see the table names are directly related to the device ID and the column names directly related to the point ID. I can add/remove points form the profile, it adds/deletes columns as needed. Apply a different profile and the DEV tables get deleted and recreated. Everything works as expected like the old program that's being replaced.
Now I need to actually do the data logging. I created a simple view:
SELECT dbo.Devices.DeviceID, dbo.Points.PointName, dbo.Points.PointID
FROM dbo.Devices LEFT OUTER JOIN
dbo.Points ON dbo.Devices.ProfileID = dbo.Points.ProfileID
Again so far so good:
DeviceID PointName PointID
5 Temp23 33
5 Hum14 34
5 Stat 35
6 Temp23 33
6 Hum14 34
6 Stat 35
I take this and I throw it in a DataTable, do a Columns.Add("Value") to it to get a blank column, then go through a data retrieval. When it's done I now have the table with the retrieved value:
DeviceID PointName PointID Value
5 Temp23 33 72.34
5 Hum14 34 43.8
5 Stat 35 1
6 Temp23 33 76.80
6 Hum14 34 54.2
6 Stat 35 0
And that's where I'm stuck. I need to take this info, use the DeviceID for the table name and the PointID for the column name, and insert the data. In otherwords I need this:
Dim myParamList As New Dictionary(Of String, Object) From {
{"#SampleTime", Date.Now},
{"#DevTable", "Dev" & r.Item("DeviceID")},
HOW DO I CYCLE THROUGH TO GET THE COLUMNS HERE?
}
UpdateDatabase(MySQLConnection, "INSERT INTO #DevTable (SampleTime, AND HERE?) VALUES (#SampleTime, AND HERE)", myParamList)
I cannot figure out the cycling through part. I thought I should use a Count + Group By to find out how many rows have the same device ID, like DeviceID 5 has 3 rows, and use that to cycle through that number of times but I'm just stuck trying to figure out how.
Any suggestions on the best way to do this?

Answer 1

So after struggling with trying to do a GroupBy on a dataview I decided to just do another database query with a Count(*) and GroupBy DeviceID to grab my unique DeviceIDs:
DeviceID RowCount
5 3
6 3
I then used that to loop through the device ID's and used the ID to filter myView as needed. Then I dynamically created a parameterized SQL string and update the database:
For Each r As DataRow In DevIDDataset.Tables("DeviceIDs").Rows
myView.RowFilter = "DeviceID=" & r.Item("DeviceID")
Dim myParamList As New Dictionary(Of String, Object) From {
{"#SampleTime", Date.Now}
}
Dim myFields As String = "SampleTime"
Dim myValues As String = "#SampleTime"
For Each row As DataRowView In myView
Dim myPointID As String = row.Item("PointID")
myFields += ",obj" & myPointID
myParamList.Add("#obj" & myPointID, row.Item("RetrievedValue"))
myValues += ",#obj" & myPointID
Next
UpdateDatabase(MySQLConnection, "INSERT INTO dev" & r.Item("DeviceID") & " (" & myFields & ") VALUES (" & myValues & ")", myParamList)
Next
Not pretty but it does what it needs to do and I can't think of any other way to do it.