Method: Webhookdb::Replicator::Base#_upsert_update_expr

Defined in:

lib/webhookdb/replicator/base.rb

#_upsert_update_expr(inserting, enrichment: nil) ⇒ Object

Given the hash that is passed to the Sequel insert (so contains all columns, including those from _prepare_for_insert), return the hash used for the insert_conflict(update:) keyword args.

Rather than sending over the literal values in the inserting statement (which is pretty verbose, like the large ‘data’ column), make a smaller statement by using ‘EXCLUDED’.

This can be overriden when the service requires different values for inserting vs. updating, such as when a column’s update value must use the EXCLUDED table in the upsert expression.

Most commonly, the use case for this is when you want to provide a row a value, but ONLY on insert, OR on update by ONLY if the column is nil. In that case, pass the result of this base method to _coalesce_excluded_on_update (see also for more details).

You can also use this method to merge :data columns together. For example: ‘super_result = Sequel.lit(“#Webhookdb::Replicator::Base.selfself.service_integrationself.service_integration.table_name.data || excluded.data”)`

By default, this will use the same values for UPDATE as are used for INSERT, like ‘email = EXCLUDED.email` (the ’EXCLUDED’ row being the one that failed to insert).

# File 'lib/webhookdb/replicator/base.rb', line 851

def _upsert_update_expr(inserting, enrichment: nil)
  result = inserting.each_with_object({}) { |(c, _), h| h[c] = Sequel[:excluded][c] }
  return result
end