Add support for Map data types in the schema

lib/active_record/connection_adapters/clickhouse/oid/map.rb

@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+module ActiveRecord
+  module ConnectionAdapters
+    module Clickhouse
+      module OID # :nodoc:
+        class Map < Type::Value # :nodoc:
+          def initialize(sql_type)
+            match_data = /map\(([^,]+),\s([^\)]+)\)/i.match(sql_type)
+            @key_type = ClickhouseAdapter::TYPE_MAP.lookup(match_data[1])
+            @value_type = ClickhouseAdapter::TYPE_MAP.lookup(match_data[2])
+          end
+
+          def type
+            @value_type.type
+          end
+
+          def key_type
+            @key_type.type
+          end
+
+          def serialize(value)
+            if value.is_a?(Hash)
+              value.each_with_object({}) { |(k, v), h| h[@key_type.serialize(k)] = @value_type.serialize(v) }
+            else
+              super
+            end
+          end
+        end
+      end
+    end
+  end
+end

lib/active_record/connection_adapters/clickhouse/schema_creation.rb

@@ -34,6 +34,10 @@ def add_column_options!(sql, options)
           if options[:array]
             sql.gsub!(/\s+(.*)/, ' Array(\1)')
           end
+          if options[:map]
+            key_type = ClickhouseAdapter::NATIVE_DATABASE_TYPES.dig(options[:map],:name)
+            sql.gsub!(/\s+(.*)/, " Map(#{key_type}, \\1)")
+          end
           sql.gsub!(/(\sString)\(\d+\)/, '\1')
           sql << " DEFAULT #{quote_default_expression(options[:default], options[:column])}" if options_include_default?(options)
           sql

lib/active_record/connection_adapters/clickhouse_adapter.rb

@@ -7,6 +7,7 @@
 require 'active_record/connection_adapters/clickhouse/oid/array'
 require 'active_record/connection_adapters/clickhouse/oid/date'
 require 'active_record/connection_adapters/clickhouse/oid/date_time'
+require 'active_record/connection_adapters/clickhouse/oid/map'
 require 'active_record/connection_adapters/clickhouse/oid/uuid'
 require 'active_record/connection_adapters/clickhouse/oid/big_integer'
 require 'active_record/connection_adapters/clickhouse/schema_definitions'
@@ -235,18 +236,26 @@ def initialize_type_map(m) # :nodoc:
           m.register_type(%r(Array)) do |sql_type|
             Clickhouse::OID::Array.new(sql_type)
           end
+
+          m.register_type(%r(Map)) do |sql_type|
+            Clickhouse::OID::Map.new(sql_type)
+          end
         end
       end
 
+      TYPE_MAP = Type::TypeMap.new.tap { |m| ClickhouseAdapter.initialize_type_map(m) }
+
       # In Rails 7 used constant TYPE_MAP, we need redefine method
       def type_map
-        @type_map ||= Type::TypeMap.new.tap { |m| ClickhouseAdapter.initialize_type_map(m) }
+        TYPE_MAP
       end
 
       def quote(value)
         case value
         when Array
           '[' + value.map { |v| quote(v) }.join(', ') + ']'
+        when Hash
+          '{' + value.map { |k, v| "#{quote(k)}: #{quote(v)}" }.join(', ') + '}'
         else
           super
         end

lib/clickhouse-activerecord/schema_dumper.rb

@@ -151,10 +151,16 @@ def schema_array(column)
       (column.sql_type =~ /Array?\(/).nil? ? nil : true
     end
 
+    def schema_map(column)
+      match_data = /Map\(([^,]+)/.match(column.sql_type)
+      match_data.nil? ? nil : ":" + match_data[1].downcase
+    end
+
     def prepare_column_options(column)
       spec = {}
       spec[:unsigned] = schema_unsigned(column)
       spec[:array] = schema_array(column)
+      spec[:map] = schema_map(column)
       spec.merge(super).compact
     end
   end