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Import Rows between 2 datasets for all tables with matching columns

Hi there,

I have a rather unusual situation of which I would greatly appreciate some help on. Basically I have a typed ADO.Net Dataset that does not contain any data just a schema with relations and all. We can call this CurrentDataSet, it has about 56 tables in it..(I know right not very clever).

Anyway, I use this dataset to bind data to controls on a specific form with tabs. OK hope that is clear. Now I am getting the data from an API call which returns XML Data of which I then read and create a new Dataset from this using the below method:

  Dim web As New WebClient()
            Dim url As String = String.Format("https://test.co.uk/api/company?id=12345&apiKey=xxxx")
            Dim response As String = web.DownloadString(url)

            Dim ds As New DataSet()
          
            Using stringReader As New StringReader(response)
                ds = New DataSet
                ds.ReadXml(stringReader)
            End Using

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I then can get the datatables from this new Dataset using ds.Tables("TableName"). However what I would like to do is populate CurrentDataSet with the data that comes from ds, so that it would be easier for me to use the bindingsource from CurrentDataset to bind to my controls. I know you can use the importrow method to import rows into CurrentDataSet...but there is a major caveat.

The problem is that the returned datatables from the API call aren't always present if there is no information in them. The API only returns datatables and fields from the relevant datatables if there are rows or data in them.

CurrentDataSet contains all possible fields and tables that the API could possibly return, now I want to know how I can update CurrentDataSet with row items only where table and field names exist between ds and CurrentDataSet? Ideally if I could merge the new dataset(ds) into matching tables/field in one go rather than looping through each datatable and columns, that would be great

I am putting maxmimum points on this because I think it is really difficult, thanks in advance.
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databarracks
Asked:
databarracks
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1 Solution
 
CodeCruiserCommented:
DataTable.Merge method does not require the schema of two datatables to be same. It can merge the columns that exist in both datatables. You can also control how it deals with additional columns that exist in source table but not in target table.

http://msdn.microsoft.com/en-us/library/wtk78t63(v=vs.110).aspx

Give it a try.
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databarracksAuthor Commented:
I have tried this in code but it  didn't work as it kept saying that the column already exists or datatype integer keys already exist etc.
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CodeCruiserCommented:
Can you show the code?
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databarracksAuthor Commented:
  Dim web As New WebClient()
            Dim url As String = String.Format("https://test.co.uk/api/company?id=12345&apiKey=xxxx")
            Dim response As String = web.DownloadString(url)

            Dim ds As New DataSet()
          
            Using stringReader As New StringReader(response)
                ds = New DataSet
                ds.ReadXml(stringReader)
            End Using

CurrentDataSet.Merge(ds,True,MissingMappingAction.Add)

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So I have tries MissingMappingAction.Ignore and still breaks. THe CurrentDataSet is placed on my form at design time
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CodeCruiserCommented:
I would recommend merging datatables instead of datasets.

Also, you need an instance of the CurrentDataSet to merge with.
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databarracksAuthor Commented:
Ok could you show me a code snippet of your plan?
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CodeCruiserCommented:
Create an populate an instance of CurrentDataSet

Dim OriginalDataSet As New CurrentDataSet
MyTableAdapter.Fill(OriginalDataSet)

Dim NewDataSet As New DataSet
MyNewTableAdapter.Fill(NewDataSet)

OriginalDataSet.Tables(0).Merge(NewDataSet.Tables(0))


Notice that above line assumes that Tables(0) of OriginalDataSet and Tables(0) of NewDataSet are corresponding tables that you want to merge.
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databarracksAuthor Commented:
Hi CodeCruiser,

I have tried your approach and I get the below error

<target>.id and <source>.id have conflicting properties: DataType property mismatch.

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Also please be aware that I don't have any TableAdapter's for my datasets due to the nature of the returned api
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CodeCruiserCommented:
So you have same columns in both tables but these columns have different datatype in each table. Can you confirm which column it is and why it has different datatypes?
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databarracksAuthor Commented:
HI there it is saying that the primary key field has different data types but they both have Int32 data types. To be honest because of the nature of the api I just don't see a way that I am going to get this to work as it doesn't always return all the fields from the table if there is no information in the column.

It is really annoying but I might just bind the new dataset from the api directly onto my forms instead of using my permanent dataset. I built the dataset using an XML to XSD converter in VS2012 if that helps.
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CodeCruiserCommented:
Can you show code that you use to populate the permanent dataset, the new dataset and the merge code?
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databarracksAuthor Commented:
Hi there,

Apologies for abandoning this question. I worked around this by simply trapping loads of possible scenarios as it just wasn't feasible any other way.

Thanks for the guidance as always CodeCruiser
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databarracksAuthor Commented:
Very helpful as always
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