support cse in the with clause

Author: PNixx

CHANGELOG.md

@@ -1,3 +1,13 @@
+### Version 1.6.0 (Jan 19, 2026)
+
+* Support CSE (Common Scalar Expressions) in the `WITH` clause
+* Fix regex to match FROM keyword, not column names containing 'from' #220
+* Add JSON column type support #209
+* Support execute_batch #216
+* Add disconnect method to adapter #186
+* Add check_current_protected_environment! to Tasks #222
+* Do not truncate engines that cannot be truncated #226
+
 ### Version 1.5.1 (Nov 6, 2025)
 
 * Fix rake tasks

lib/arel/visitors/clickhouse.rb

@@ -18,6 +18,33 @@ def aggregate(name, o, collector)
         end
       end
 
+      # https://clickhouse.com/docs/sql-reference/statements/select/with
+      def visit_Arel_Nodes_Cte(o, collector)
+        is_cse = o.relation.is_a?(Symbol)
+
+        if is_cse && o.name.is_a?(String)
+          collector << quote(o.name)
+        elsif is_cse && o.name.is_a?(ActiveRecord::Relation)
+          visit o.name.arel, collector
+        else
+          collector << quote_table_name(o.name)
+        end
+        collector << " AS "
+
+        case o.materialized
+        when true
+          collector << "MATERIALIZED "
+        when false
+          collector << "NOT MATERIALIZED "
+        end
+
+        if is_cse
+          collector << o.relation.to_s
+        else
+          visit o.relation, collector
+        end
+      end
+
       # https://clickhouse.com/docs/en/sql-reference/statements/delete
       # DELETE and UPDATE in ClickHouse working only without table name
       def visit_Arel_Attributes_Attribute(o, collector)

lib/clickhouse-activerecord.rb

@@ -4,6 +4,7 @@
 
 require 'core_extensions/active_record/internal_metadata'
 require 'core_extensions/active_record/relation'
+require 'core_extensions/active_record/relation/query_methods'
 require 'core_extensions/active_record/schema_migration'
 require 'core_extensions/active_record/migration/command_recorder'
 require 'core_extensions/arel/nodes/select_core'
@@ -24,6 +25,7 @@ def self.load
     ActiveRecord::InternalMetadata.prepend(CoreExtensions::ActiveRecord::InternalMetadata)
     ActiveRecord::Migration::CommandRecorder.include(CoreExtensions::ActiveRecord::Migration::CommandRecorder)
     ActiveRecord::Relation.prepend(CoreExtensions::ActiveRecord::Relation)
+    ActiveRecord::QueryMethods.prepend(CoreExtensions::ActiveRecord::QueryMethods)
     ActiveRecord::SchemaMigration.prepend(CoreExtensions::ActiveRecord::SchemaMigration)
 
     Arel::Nodes::SelectCore.prepend(CoreExtensions::Arel::Nodes::SelectCore)

lib/clickhouse-activerecord/version.rb

@@ -1,3 +1,3 @@
 module ClickhouseActiverecord
-  VERSION = '1.5.1'
+  VERSION = '1.6.0'
 end

lib/core_extensions/active_record/relation.rb

@@ -6,16 +6,6 @@ def self.prepended(base)
         base::VALID_UNSCOPING_VALUES << :final << :settings
       end
 
-      def reverse_order!
-        return super unless connection.is_a?(::ActiveRecord::ConnectionAdapters::ClickhouseAdapter)
-
-        orders = order_values.uniq.reject(&:blank?)
-        return super unless orders.empty? && !primary_key
-
-        self.order_values = (column_names & %w[date created_at]).map { |c| arel_table[c].desc }
-        self
-      end
-
       # Define settings in the SETTINGS clause of the SELECT query. The setting value is applied only to that query and is reset to the default or previous value after the query is executed.
       # For example:
       #

lib/core_extensions/active_record/relation/query_methods.rb

@@ -0,0 +1,26 @@
+module CoreExtensions
+  module ActiveRecord
+    module QueryMethods
+
+      def reverse_order!
+        return super unless connection.is_a?(::ActiveRecord::ConnectionAdapters::ClickhouseAdapter)
+
+        orders = order_values.uniq.reject(&:blank?)
+        return super unless orders.empty? && !primary_key
+
+        self.order_values = (column_names & %w[date created_at]).map { |c| arel_table[c].desc }
+        self
+      end
+
+      def build_with_expression_from_value(value, nested = false)
+        case value
+        when Symbol
+          value
+        else
+          super
+        end
+      end
+
+    end
+  end
+end

spec/single/model_spec.rb

@@ -467,6 +467,37 @@ class ModelPk < ActiveRecord::Base
         expect(sql).to eq('SELECT sample.* FROM sample GROUP BY GROUPING SETS ( ( foo, bar ), ( sample.baz ) )')
       end
     end
+
+    describe '#cte & cse:' do
+      it 'cte string' do
+        sql = Model.with('t' => ModelJoin.where(event_name: 'test')).where(event_name: Model.from('f').select('event_name')).to_sql
+        expect(sql).to eq('WITH t AS (SELECT joins.* FROM joins WHERE joins.event_name = \'test\') SELECT sample.* FROM sample WHERE sample.event_name IN (SELECT event_name FROM f)')
+      end
+
+      it 'cte symbol' do
+        sql = Model.with(t: ModelJoin.where(event_name: 'test')).where(event_name: Model.from('f').select('event_name')).to_sql
+        expect(sql).to eq('WITH t AS (SELECT joins.* FROM joins WHERE joins.event_name = \'test\') SELECT sample.* FROM sample WHERE sample.event_name IN (SELECT event_name FROM f)')
+      end
+
+      it 'cse string variable' do
+        sql = Model.with('2026-01-01 15:23:00' => :t).where(Arel.sql('date = toDate(t)')).to_sql
+        expect(sql).to eq('WITH \'2026-01-01 15:23:00\' AS t SELECT sample.* FROM sample WHERE (date = toDate(t))')
+      end
+
+      it 'cse symbol function' do
+        sql = Model.with('(id, extension) -> concat(lower(id), extension)': :t).where(Arel.sql('date = toDate(t)')).to_sql
+        expect(sql).to eq('WITH (id, extension) -> concat(lower(id), extension) AS t SELECT sample.* FROM sample WHERE (date = toDate(t))')
+      end
+
+      it 'cse query relation' do
+        sql = Model.with(ModelJoin.select(Arel.sql('min(date)')) => :min_date).where(Arel.sql('date = min_date')).to_sql
+        expect(sql).to eq('WITH (SELECT min(date) FROM joins) AS min_date SELECT sample.* FROM sample WHERE (date = min_date)')
+      end
+
+      it 'cse error' do
+        expect { Model.with('2026-01-01 15:23:00' => 't').where(Arel.sql('date = toDate(t)')).to_sql }.to raise_error(ArgumentError)
+      end
+    end
   end
 
   context 'sample with id column' do