Problem changing table structure CDS

Question

I created a table using a .hdbdd file.  I was then able to import data from a csv file.  Everything worked like a charm.  Later I tried to add a field to the table but when I tried to save the updated hdbdd and csv files I get an error that the number of columns in the table and csv file don't match.  So, I tried to delete the entry for the table from the hdbti table.  It allowed me to save the file but still get the column mismatch error. 
Then I deleted the database table but now I get an error: Table import target table cannot be found. Table import target table cannot be found.
Finally, I tried to delete the csv file but the file appears in the list of files but I can't open it and I still get the same error.
Now I can't change any part of the data model with getting the error.  Is there no way out of this maze?
Ross

Answer 1

My package structure:
The hdbdd file (The customers file is the one I want to delete):
If I activate this file, it activates fine but if I delete the customer table definition I get the error "Error while activating /f14e/S001/GBI/data/GBI_S001.hdbdd:Unknown object name "f14e.S001.GBI.data::GBI_S001.CUSTOMERS"."
namespace f14e.S001.GBI.data;
@Schema: 'F14E_STUDENT_001'
context GBI_S001 {
    @Catalog.tableType: #COLUMN
  entity SALES_ORG {
  key SALES_ORG  : String(4);
  DESCRIPTION : String(16);
@Catalog.tableType: #COLUMN
  entity CUSTOMERS {
  key ID : String(10);
  COMPANY_NAME : String(35);
  CITY : String(20);
  key SALES_ORG : String(4);
  COUNTRY: String(2);
  @Catalog.tableType: #COLUMN
  entity PRODUCTS {
  key product : String(8);
  product_name : String(40);
  product_category : String(3);
  division : String(2);
  internal_price: Decimal(17,3);
  price: Decimal(17,3);
  color: String(10);
  product_group: String(20);
  @Catalog.tableType: #COLUMN
  entity SALES_ORDERS {
         created_at : LocalDate;
         created_by : String(20);
     customer_number : String(10);
  key order_number : String(10);
     gross_amount : Decimal(17,3);
     discount : Decimal(17,3);
     currency : String(3);
     status : String(15);
    @Catalog.tableType: #COLUMN
  entity SALES_ORDER_DETAILS {
  key order_number : String(10);
  key order_item : String(3);
     product : String(8);
     quantity : Integer;
     unit_of_measure : String(3);
     revenue : Decimal(17,3);
     currency : String(3);
     discount : Decimal(17,3);
Tables in the catalog
Customer table structure
hdbti file (with other tables removed)
import = [
  table = "f14e.S001.GBI.data::GBI_S001.CUSTOMERS";
  schema = "F14A_STUDENT_001";
  file = "f14e.S001.GBI.data:customers2.csv";
  header = false;
If I attempt to activate this file I get the error "Error while activating /f14e/S001/GBI/data/importdata.hdbti:Table import target table cannot be found. Table import target table cannot be found."
I appreciate your help on this.
Ross