database create / drop, migration support with rake tasks

README.md

@@ -1,6 +1,6 @@
 # Clickhouse::Activerecord
 
-A Ruby database ActiveRecord driver for ClickHouse. Support Rails >= 5.0.
+A Ruby database ActiveRecord driver for ClickHouse. Support Rails >= 5.2.
 
 ## Installation
 
@@ -59,10 +59,30 @@ development:
   password: password
 ```
 
-Schema dump:
+### Rake tasks
+
+Create / drop / purge / reset database:
+ 
+    $ rake clickhouse:create
+    $ rake clickhouse:drop
+    $ rake clickhouse:purge
+    $ rake clickhouse:reset
+    
+Migration:
+
+    $ rails g clickhouse_migration MIGRATION_NAME COLUMNS
+    $ rake clickhouse:migrate
+    
+Rollback migration not supported!
+
+Schema dump to `db/clickhouse_schema.rb` file:
 
     $ rake clickhouse:schema:dump
 
+Schema load from `db/clickhouse_schema.rb` file:
+
+    $ rake clickhouse:schema:load
+
 We use schema for emulate development or tests environment on PostgreSQL adapter.
 
 ### Insert and select data
@@ -81,8 +101,6 @@ ActionView.maximum(:date)
 #=> 'Wed, 29 Nov 2017'
 ```
 
-NOTE: Creating tables in developing.
-
 ## Donations
 
 Donations to this project are going directly to [PNixx](https://github.com/PNixx), the original author of this project:

lib/active_record/connection_adapters/clickhouse/schema_creation.rb

@@ -10,6 +10,7 @@ def visit_AddColumnDefinition(o)
         end
 
         def add_column_options!(sql, options)
+          sql << " DEFAULT #{quote_default_expression(options[:default], options[:column])}" if options_include_default?(options)
           if options[:null] || options[:null].nil?
             sql.gsub!(/\s+(.*)/, ' Nullable(\1)')
           end

lib/active_record/connection_adapters/clickhouse/schema_statements.rb

@@ -112,7 +112,7 @@ def process_response(res)
         end
 
         def log_with_debug(sql, name = nil)
-          return yield unless self.pool.spec.config[:debug]
+          return yield unless @debug
           log(sql, "#{name} (system)") { yield }
         end
 
@@ -127,7 +127,10 @@ def create_table_definition(*args)
         def new_column_from_field(table_name, field)
           sql_type = field[1]
           type_metadata = fetch_type_metadata(sql_type)
-          ClickhouseColumn.new(field[0], field[3].present? ? field[3] : nil, type_metadata, field[1].include?('Nullable'), table_name, nil)
+          default = field[3]
+          default_value = extract_value_from_default(default)
+          default_function = extract_default_function(default_value, default)
+          ClickhouseColumn.new(field[0], default_value, type_metadata, field[1].include?('Nullable'), table_name, default_function)
         end
 
         protected
@@ -142,6 +145,35 @@ def table_structure(table_name)
             "Could not find table '#{table_name}'"
         end
         alias column_definitions table_structure
+
+        private
+
+        # Extracts the value from a PostgreSQL column default definition.
+        def extract_value_from_default(default)
+          case default
+            # Quoted types
+          when /\Anow\(\)\z/m
+            nil
+            # Boolean types
+          when "true".freeze, "false".freeze
+            default
+            # Object identifier types
+          when /\A-?\d+\z/
+            $1
+          else
+            # Anything else is blank, some user type, or some function
+            # and we can't know the value of that, so return nil.
+            nil
+          end
+        end
+
+        def extract_default_function(default_value, default) # :nodoc:
+          default if has_default_function?(default_value, default)
+        end
+
+        def has_default_function?(default_value, default) # :nodoc:
+          !default_value && (%r{\w+\(.*\)} === default)
+        end
       end
     end
   end

lib/active_record/connection_adapters/clickhouse_adapter.rb

@@ -25,7 +25,7 @@ def clickhouse_connection(config)
           raise ArgumentError, 'No database specified. Missing argument: database.'
         end
 
-        ConnectionAdapters::ClickhouseAdapter.new(nil, logger, [host, port], { user: config[:username], password: config[:password], database: database }.compact)
+        ConnectionAdapters::ClickhouseAdapter.new(nil, logger, [host, port], { user: config[:username], password: config[:password], database: database }.compact, config[:debug])
       end
     end
   end
@@ -45,43 +45,6 @@ def is_view=(value)
   module ConnectionAdapters
     class ClickhouseColumn < Column
 
-      private
-
-      # Extracts the value from a PostgreSQL column default definition.
-      def extract_value_from_default(default)
-        case default
-          # Quoted types
-        when /\A[\(B]?'(.*)'.*::"?([\w. ]+)"?(?:\[\])?\z/m
-          # The default 'now'::date is CURRENT_DATE
-          if $1 == "now".freeze && $2 == "date".freeze
-            nil
-          else
-            $1.gsub("''".freeze, "'".freeze)
-          end
-          # Boolean types
-        when "true".freeze, "false".freeze
-          default
-          # Numeric types
-        when /\A\(?(-?\d+(\.\d*)?)\)?(::bigint)?\z/
-          $1
-          # Object identifier types
-        when /\A-?\d+\z/
-          $1
-        else
-          # Anything else is blank, some user type, or some function
-          # and we can't know the value of that, so return nil.
-          nil
-        end
-      end
-
-      def extract_default_function(default_value, default) # :nodoc:
-        default if has_default_function?(default_value, default)
-      end
-
-      def has_default_function?(default_value, default) # :nodoc:
-        !default_value && (%r{\w+\(.*\)} === default)
-      end
-
     end
 
     class ClickhouseAdapter < AbstractAdapter
@@ -101,10 +64,11 @@ class ClickhouseAdapter < AbstractAdapter
       include Clickhouse::SchemaStatements
 
       # Initializes and connects a Clickhouse adapter.
-      def initialize(connection, logger, connection_parameters, config)
+      def initialize(connection, logger, connection_parameters, config, debug = false)
         super(connection, logger)
         @connection_parameters = connection_parameters
         @config = config
+        @debug = debug
 
         @prepared_statements = false
 
@@ -169,6 +133,28 @@ def create_schema_dumper(options) # :nodoc:
         ClickhouseActiverecord::SchemaDumper.create(self, options)
       end
 
+      # Create a new ClickHouse database.
+      def create_database(name)
+        sql = "CREATE DATABASE #{quote_table_name(name)}"
+        log_with_debug(sql, adapter_name) do
+          res = @connection.post("/?#{@config.except(:database).to_param}", "CREATE DATABASE #{quote_table_name(name)}")
+          process_response(res)
+        end
+      end
+
+      # Drops a ClickHouse database.
+      def drop_database(name) #:nodoc:
+        sql = "DROP DATABASE IF EXISTS #{quote_table_name(name)}"
+        log_with_debug(sql, adapter_name) do
+          res = @connection.post("/?#{@config.except(:database).to_param}", sql)
+          process_response(res)
+        end
+      end
+
+      def drop_table(table_name, options = {}) # :nodoc:
+        do_execute "DROP TABLE#{' IF EXISTS' if options[:if_exists]} #{quote_table_name(table_name)}"
+      end
+
       protected
 
       def last_inserted_id(result)

lib/clickhouse-activerecord.rb

@@ -5,6 +5,8 @@
 if defined?(Rails::Railtie)
   require 'clickhouse-activerecord/railtie'
   require 'clickhouse-activerecord/schema_dumper'
+  require 'clickhouse-activerecord/tasks'
+  ActiveRecord::Tasks::DatabaseTasks.register_task(/clickhouse/, "ClickhouseActiverecord::Tasks")
 end
 
 module ClickhouseActiverecord

lib/clickhouse-activerecord/tasks.rb

@@ -0,0 +1,65 @@
+# frozen_string_literal: true
+
+module ClickhouseActiverecord
+  class Tasks
+
+    delegate :connection, :establish_connection, :clear_active_connections!, to: ActiveRecord::Base
+
+    def initialize(configuration)
+      @configuration = configuration
+    end
+
+    def create
+      establish_master_connection
+      connection.create_database @configuration["database"]
+    rescue ActiveRecord::StatementInvalid => e
+      if e.cause.to_s.include?('already exists')
+        raise ActiveRecord::Tasks::DatabaseAlreadyExists
+      else
+        raise
+      end
+    end
+
+    def drop
+      establish_master_connection
+      connection.drop_database @configuration["database"]
+    end
+
+    def purge
+      clear_active_connections!
+      drop
+      create
+    end
+
+    def migrate
+      check_target_version
+
+      verbose = ENV["VERBOSE"] ? ENV["VERBOSE"] != "false" : true
+      scope = ENV["SCOPE"]
+      verbose_was, ActiveRecord::Migration.verbose = ActiveRecord::Migration.verbose, verbose
+      binding.pry
+      connection.migration_context.migrate(target_version) do |migration|
+        scope.blank? || scope == migration.scope
+      end
+      ActiveRecord::Base.clear_cache!
+    ensure
+      ActiveRecord::Migration.verbose = verbose_was
+    end
+
+    private
+
+    def establish_master_connection
+      establish_connection @configuration
+    end
+
+    def check_target_version
+      if target_version && !(ActiveRecord::Migration::MigrationFilenameRegexp.match?(ENV["VERSION"]) || /\A\d+\z/.match?(ENV["VERSION"]))
+        raise "Invalid format of target version: `VERSION=#{ENV['VERSION']}`"
+      end
+    end
+
+    def target_version
+      ENV["VERSION"].to_i if ENV["VERSION"] && !ENV["VERSION"].empty?
+    end
+  end
+end

lib/clickhouse-activerecord/version.rb

@@ -1,3 +1,3 @@
 module ClickhouseActiverecord
-  VERSION = '0.3.0'
+  VERSION = '0.3.1'
 end

lib/generators/clickhouse_migration_generator.rb

@@ -0,0 +1,11 @@
+require 'rails/generators/active_record/migration/migration_generator'
+
+class ClickhouseMigrationGenerator < ActiveRecord::Generators::MigrationGenerator
+  source_root File.join(File.dirname(ActiveRecord::Generators::MigrationGenerator.instance_method(:create_migration_file).source_location.first), "templates")
+
+  def create_migration_file
+    set_local_assigns!
+    validate_file_name!
+    migration_template @migration_template, "db/migrate_clickhouse/#{file_name}.rb"
+  end
+end

lib/tasks/clickhouse.rake

@@ -2,12 +2,17 @@
 
 namespace :clickhouse do
 
+  task load_config: :environment do
+    ENV['SCHEMA'] = "db/clickhouse_schema.rb"
+    ActiveRecord::Migrator.migrations_paths = ["db/migrate_clickhouse"]
+    ActiveRecord::Base.establish_connection(:"#{Rails.env}_clickhouse")
+  end
+
   namespace :schema do
 
     # todo not testing
     desc 'Load database schema'
-    task load: :environment do
-      ActiveRecord::Base.establish_connection(:"#{Rails.env}_clickhouse")
+    task load: :load_config do
       load("#{Rails.root}/db/clickhouse_schema.rb")
     end
 
@@ -22,4 +27,29 @@ namespace :clickhouse do
 
   end
 
+  desc 'Creates the database from DATABASE_URL or config/database.yml'
+  task create: [:load_config] do
+    ActiveRecord::Tasks::DatabaseTasks.create(ActiveRecord::Base.configurations["#{Rails.env}_clickhouse"])
+  end
+
+  desc 'Drops the database from DATABASE_URL or config/database.yml'
+  task drop: [:load_config, 'db:check_protected_environments'] do
+    ActiveRecord::Tasks::DatabaseTasks.drop(ActiveRecord::Base.configurations["#{Rails.env}_clickhouse"])
+  end
+
+  desc 'Empty the database from DATABASE_URL or config/database.yml'
+  task purge: [:load_config, 'db:check_protected_environments'] do
+    ActiveRecord::Tasks::DatabaseTasks.purge(ActiveRecord::Base.configurations["#{Rails.env}_clickhouse"])
+  end
+
+  # desc 'Resets your database using your migrations for the current environment'
+  task reset: :load_config do
+    Rake::Task['clickhouse:purge'].execute
+    Rake::Task['clickhouse:migrate'].execute
+  end
+
+  desc 'Migrate the clickhouse database'
+  task migrate: :load_config do
+    Rake::Task['db:migrate'].execute
+  end
 end