Add Table.delete_rows function allowing deleting rows in a database table.

[jdunkerley]

• Just a Database API. In-Memory should have an Unsupported Operation (join Left Exclusive has same result).
• For Database, ony can act on a trivial table (as per update_datebase_table).
• Locked behind the Output context.
• Dry run doesn't affect the table but should compute the row_count.
• Source table should be able to be either in-memory (silent upload) or in-database (same connection),

Table.delete_rows
    self -> ## Trivial Table whose rows are will be deleted.
    key_values_to_delete : Table -> ## Extra columns are ignored, primary key columns must exist and must map by name.
    (key_columns : Vector | Nothing = default_key_columns self) -> ## By default uses the primary key of self.
    Integer (row_count of deleted)

For example, my_students.delete_rows (student_leaving_table) ["first_name", "last_name"] returning number of rows (e.g. 31).

Additionally, we should add a function is to delete all rows.
Connection.truncate_table target_table:Table -> Integer returning the row count of deleted.
Similar to drop_table.

Additionally, flip update_database_table to be consistent:

Table.update_rows
    self ->  ## Trivial Table whose rows are will be updated.
    source_table:Table -> ## Set of data
    (update_action : Update_Action = Update_Action.Update_Or_Insert) ->
    (key_columns : Vector | Nothing = default_key_columns self) ->
    (error_on_missing_columns : Boolean = False)
    (on_problems : Problem_Behavior = Problem_Behavior.Report_Warning) 

[jdunkerley]

Aim to review on Tuesday 11th

[jdunkerley]

Do we feel that a "filter_rows" where we produce effectively the result but in a query state is useful?

• Equivalent to a Left Exclusive join effectively.

[enso-bot]

Radosław Waśko reports a new STANDUP for yesterday (2023-08-29):

Progress: Adding new APIs for delete_rows. Clarifying spec and writing docs. Lots of meetings. Drafting a doc on an MVP for library sharing. It should be finished by 2023-09-01.

Next Day: Next day I will be working on the same task. Finish the libraries doc. Update update_rows API. Write tests for delete_rows.

[enso-bot]

Radosław Waśko reports a new STANDUP for today (2023-08-30):

Progress: Posted the libraries "roadmap" doc. Updated the update_rows API - I think the new shape reads much better indeed. Written (I think quite comprehensive set of) tests for delete_rows. It should be finished by 2023-09-01.

Next Day: Next day I will be working on the same task. Implement delete_rows

[enso-bot]

Radosław Waśko reports a new STANDUP for yesterday (2023-08-31):

Progress: Finished the delete_rows implementation - PR ready for review. Fixing the pending library resolution PR - some errors that I have overlooked earlier. Discussions on Data.post etc. It should be finished by 2023-09-01.

Next Day: Next day I will be working on the #7354 task. Ensure the libraries resolution PR gets merged. Start next task - fixing small defects I found earlier.