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@checkbutton
Created March 21, 2016 20:59
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Support for PostgreSQL enum types in Rails 4.2 (including schema dump)
module ActiveRecord
class SchemaDumper
def dump(stream)
header(stream)
extensions(stream)
enums(stream)
tables(stream)
trailer(stream)
stream
end
private
def enums(stream)
enum_types = @connection.enum_types
if enum_types.any?
stream.puts " # These are custom enum types that must be created before they can be used in the schema definition"
enum_types.each do |enum_type|
stream.puts " create_enum \"#{enum_type.first}\", \"#{enum_type.second.join('", "')}\""
end
stream.puts
end
end
end
module ConnectionAdapters
class PostgreSQLAdapter
def native_database_types
NATIVE_DATABASE_TYPES.merge(enum: { name: "enum" })
end
def column_spec(column, types)
spec = prepare_column_options(column, types)
(spec.keys - [:name, :type, :enum_type]).each{ |k| spec[k].insert(0, "#{k}: ")}
spec
end
def prepare_column_options(column, types)
spec = super
spec[:type] = column.type == :enum ? 'column' : spec[:type]
spec[:enum_type] = column.sql_type.inspect if column.type == :enum
spec[:array] = 'true' if column.respond_to?(:array) && column.array
spec[:default] = "\"#{column.default_function}\"" if column.default_function
spec
end
def migration_keys
super.insert(1, :enum_type) << :array
end
def enum_types
query = <<-SQL
SELECT t.typname AS enum_name,
string_agg(e.enumlabel, ' ') AS enum_value
FROM pg_type t
JOIN pg_enum e ON t.oid = e.enumtypid
JOIN pg_catalog.pg_namespace n ON n.oid = t.typnamespace
WHERE n.nspname = 'public'
GROUP BY enum_name
SQL
res = exec_query(query, 'SCHEMA').cast_values
res.each do |line|
line[1] = line[1].split(' ')
end
res
end
end
module PostgreSQL::SchemaStatements
def create_enum(name, *values)
execute "CREATE TYPE #{name} AS ENUM (#{values.map{|v| "'#{v}'"}.join(', ')})"
end
def drop_enum(name)
execute "DROP TYPE #{name}"
end
end
end
end
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