Good, after performing some transformations of my data I get the following error:
The "PROJECT" column of the "Comisiones_Agents_Particion" table contains the duplicate value "ENDESA", and this is not allowed for columns on one side of a multi-to-one relationship or for columns that are used as the primary key of a table.
OLE DB or ODBC error: HRESULT exception: 0x80040E4E.
I do not understand very well why it is due since I have made a union between several tables where the key field is Project and date and ENDESA values should be able to be duplicated since they vary in the date.
Thanks in advance.