问题
I have been tasked to write a module for importing data into a client's system. I thought to break the process into 4 parts:
1. Connect to the data source (SQL, Excel, Access, CSV, ActiveDirectory, Sharepoint and Oracle) - DONE
2. Get the available tables/data groups from the source - DONE
i. Get the available fields form the selected table/data group - DONE
ii. Get all data from the selected fields - DONE
3. Transform data to the user's requirements
4. Write the transformed data the the MSSQL target
I am trying to plan how to handle complex data transformations like:
Get column A from Table tblA, inner joined to column FA from table tblB, and concatenate these two with a semicolon in between.
OR
Get column C from table tblC on source where column tblC.D is not in table tblG column G on target database.
My worry is not the visual, but the representation in code of this operation.
I am NOT asking for sample code, but rather for some creative ideas.
The data transformation will not be with free text, but drag and drop objects that represent actions.
I am a bit lost, and need some fresh input.
回答1:
maybe you can grab some ideas from this open source project: Rhino ETL.
回答2:
See my answer: Manipulate values in a datatable?
来源：https://stackoverflow.com/questions/5388682/creating-an-etl-system-data-import-and-transformation