Created
October 25, 2018 17:13
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| task graph: :environment do | |
| result = ActiveRecord::Base.connection.execute <<~SQL | |
| select source.relname as source, dest.relname as dest | |
| from pg_catalog.pg_constraint as fk | |
| join pg_catalog.pg_class as source on source.oid = fk.conrelid | |
| join pg_catalog.pg_class as dest on dest.oid = fk.confrelid | |
| where contype = 'f'::char | |
| SQL | |
| relations = result.map(&:symbolize_keys).reduce({}) do |h, source:, dest:| | |
| h.merge(source => [dest]) { |_, a, b| a + b } | |
| end | |
| puts <<~DOT | |
| digraph fks { | |
| \tlayout=neato; | |
| \tnodesep=1; | |
| \tnode [shape=box]; | |
| #{relations.map { |table, refs| "\t#{table} -> {#{refs.join ' '}}" }.join ";\n"} | |
| } | |
| DOT | |
| end |
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