Module: EventStoreRuby::Postgres::QueryBuilder

Defined in:
lib/eventstore_ruby/postgres/query.rb

Class Method Summary collapse

Class Method Details

.build_context_query(filter_or_query) ⇒ Object

Returns [sql, params] for a SELECT query returning all matching events, ordered by ascending sequence number. Accepts an EventFilter or an EventQuery (logical OR of filters).



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# File 'lib/eventstore_ruby/postgres/query.rb', line 13

def build_context_query(filter_or_query)
  where_sql, params = compile_conditions(filter_or_query)
  ["SELECT * FROM events WHERE #{where_sql} ORDER BY sequence_number ASC", params]
end

.build_context_version_query(filter_or_query) ⇒ Object

Returns [where_sql, params] for usage inside CTEs (no SELECT/ORDER BY).



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# File 'lib/eventstore_ruby/postgres/query.rb', line 19

def build_context_version_query(filter_or_query)
  compile_conditions(filter_or_query)
end

.compile_conditions(filter_or_query) ⇒ Object

Internal helpers



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# File 'lib/eventstore_ruby/postgres/query.rb', line 27

def compile_conditions(filter_or_query)
  sql_fragments = []
  params = []

  if filter_or_query.is_a?(EventStoreRuby::EventQuery)
    filter_or_query.filters.each do |flt|
      sql_fragments << single_filter_condition(flt, params)
    end
  else
    sql_fragments << single_filter_condition(filter_or_query, params)
  end

  [sql_fragments.join(' OR '), params]
end

.pg_array_literal(strings) ⇒ Object 



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# File 'lib/eventstore_ruby/postgres/query.rb', line 6

def pg_array_literal(strings)
  '{' + strings.map { |s| s.gsub('"', '""') }.join(',') + '}'
end

.single_filter_condition(filter, params) ⇒ Object

Builds the SQL condition for a single EventFilter and pushes the corresponding parameters onto params Array. Returns the condition string wrapped in parentheses.



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# File 'lib/eventstore_ruby/postgres/query.rb', line 45

def single_filter_condition(filter, params)
  param_index = params.length + 1
  params << pg_array_literal(filter.event_types)
  condition = "event_type = ANY($#{param_index}::text[])"

  if filter.payload_predicates&.any?
    or_conditions = filter.payload_predicates.map do |predicate|
      param_index = params.length + 1
      params << predicate.to_json
      "payload @> $#{param_index}"
    end
    condition += " AND (#{or_conditions.join(' OR ')})"
  end

  "(#{condition})"
end