Merge pull request #20041 from akshay-vishnoi/sqlite_collation

SQLite3: Add collation support for string and text columns

activerecord/CHANGELOG.md

+*   SQLite: `:collation` support for string and text columns.
+
+    Example:
+
+        create_table :foo do |t|
+          t.string :string_nocase, collation: 'NOCASE'
+          t.text :text_rtrim, collation: 'RTRIM'
+        end
+
+        add_column :foo, :title, :string, collation: 'RTRIM'
+
+        change_column :foo, :title, :string, collation: 'NOCASE'
+
+    *Akshay Vishnoi*
+
 *   Allow the use of symbols or strings to specify enum values in test
     fixtures:
 

activerecord/lib/active_record/connection_adapters/sqlite3/schema_creation.rb

+module ActiveRecord
+  module ConnectionAdapters
+    module SQLite3
+      class SchemaCreation < AbstractAdapter::SchemaCreation
+        private
+          def add_column_options!(sql, options)
+            if options[:collation]
+              sql << " COLLATE \"#{options[:collation]}\""
+            end
+            super
+          end
+      end
+    end
+  end
+end

activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb

 require 'active_record/connection_adapters/abstract_adapter'
 require 'active_record/connection_adapters/statement_pool'
+require 'active_record/connection_adapters/sqlite3/schema_creation'
 
 gem 'sqlite3', '~> 1.3.6'
 require 'sqlite3'
@@ -84,6 +85,10 @@ def dealloc(stmt)
         end
       end
 
+      def schema_creation # :nodoc:
+        SQLite3::SchemaCreation.new self
+      end
+
       def initialize(connection, logger, connection_options, config)
         super(connection, logger)
 
@@ -344,9 +349,10 @@ def columns(table_name) #:nodoc:
             field["dflt_value"] = $1.gsub('""', '"')
           end
 
+          collation = field['collation']
           sql_type = field['type']
           type_metadata = fetch_type_metadata(sql_type)
-          new_column(field['name'], field['dflt_value'], type_metadata, field['notnull'].to_i == 0)
+          new_column(field['name'], field['dflt_value'], type_metadata, field['notnull'].to_i == 0, nil, collation)
         end
       end
 
@@ -441,6 +447,7 @@ def change_column(table_name, column_name, type, options = {}) #:nodoc:
             self.null    = options[:null] if options.include?(:null)
             self.precision = options[:precision] if options.include?(:precision)
             self.scale   = options[:scale] if options.include?(:scale)
+            self.collation = options[:collation] if options.include?(:collation)
           end
         end
       end
@@ -454,9 +461,9 @@ def rename_column(table_name, column_name, new_column_name) #:nodoc:
       protected
 
         def table_structure(table_name)
-          structure = exec_query("PRAGMA table_info(#{quote_table_name(table_name)})", 'SCHEMA').to_hash
+          structure = exec_query("PRAGMA table_info(#{quote_table_name(table_name)})", 'SCHEMA')
           raise(ActiveRecord::StatementInvalid, "Could not find table '#{table_name}'") if structure.empty?
-          structure
+          table_structure_with_collation(table_name, structure)
         end
 
         def alter_table(table_name, options = {}) #:nodoc:
@@ -491,7 +498,7 @@ def copy_table(from, to, options = {}) #:nodoc:
               @definition.column(column_name, column.type,
                 :limit => column.limit, :default => column.default,
                 :precision => column.precision, :scale => column.scale,
-                :null => column.null)
+                :null => column.null, collation: column.collation)
             end
             yield @definition if block_given?
           end
@@ -553,6 +560,46 @@ def translate_exception(exception, message)
             super
           end
         end
+
+      private
+        COLLATE_REGEX = /.*\"(\w+)\".*collate\s+\"(\w+)\".*/i.freeze
+
+        def table_structure_with_collation(table_name, basic_structure)
+          collation_hash = {}
+          sql            = "SELECT sql FROM
+                              (SELECT * FROM sqlite_master UNION ALL
+                               SELECT * FROM sqlite_temp_master)
+                            WHERE type='table' and name='#{ table_name }' \;"
+
+          # Result will have following sample string
+          # CREATE TABLE "users" ("id" INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
+          #                       "password_digest" varchar COLLATE "NOCASE");
+          result = exec_query(sql, 'SCHEMA').first
+
+          if result
+            # Splitting with left parantheses and picking up last will return all
+            # columns separated with comma(,).
+            columns_string = result["sql"].split('(').last
+
+            columns_string.split(',').each do |column_string|
+              # This regex will match the column name and collation type and will save
+              # the value in $1 and $2 respectively.
+              collation_hash[$1] = $2 if (COLLATE_REGEX =~ column_string)
+            end
+
+            basic_structure.map! do |column|
+              column_name = column['name']
+
+              if collation_hash.has_key? column_name
+                column['collation'] = collation_hash[column_name]
+              end
+
+              column
+            end
+          else
+            basic_structure.to_hash
+          end
+        end
     end
   end
 end

activerecord/test/cases/adapters/sqlite3/collation_test.rb

+require "cases/helper"
+require 'support/schema_dumping_helper'
+
+class SQLite3CollationTest < ActiveRecord::TestCase
+  include SchemaDumpingHelper
+
+  def setup
+    @connection = ActiveRecord::Base.connection
+    @connection.create_table :collation_table_sqlite3, force: true do |t|
+      t.string :string_nocase, collation: 'NOCASE'
+      t.text :text_rtrim, collation: 'RTRIM'
+    end
+  end
+
+  def teardown
+    @connection.drop_table :collation_table_sqlite3, if_exists: true
+  end
+
+  test "string column with collation" do
+    column = @connection.columns(:collation_table_sqlite3).find { |c| c.name == 'string_nocase' }
+    assert_equal :string, column.type
+    assert_equal 'NOCASE', column.collation
+  end
+
+  test "text column with collation" do
+    column = @connection.columns(:collation_table_sqlite3).find { |c| c.name == 'text_rtrim' }
+    assert_equal :text, column.type
+    assert_equal 'RTRIM', column.collation
+  end
+
+  test "add column with collation" do
+    @connection.add_column :collation_table_sqlite3, :title, :string, collation: 'RTRIM'
+
+    column = @connection.columns(:collation_table_sqlite3).find { |c| c.name == 'title' }
+    assert_equal :string, column.type
+    assert_equal 'RTRIM', column.collation
+  end
+
+  test "change column with collation" do
+    @connection.add_column :collation_table_sqlite3, :description, :string
+    @connection.change_column :collation_table_sqlite3, :description, :text, collation: 'RTRIM'
+
+    column = @connection.columns(:collation_table_sqlite3).find { |c| c.name == 'description' }
+    assert_equal :text, column.type
+    assert_equal 'RTRIM', column.collation
+  end
+
+  test "schema dump includes collation" do
+    output = dump_table_schema("collation_table_sqlite3")
+    assert_match %r{t.string\s+"string_nocase",\s+collation: "NOCASE"$}, output
+    assert_match %r{t.text\s+"text_rtrim",\s+collation: "RTRIM"$}, output
+  end
+end

activerecord/test/cases/adapters/sqlite3/sqlite3_adapter_test.rb

@@ -421,14 +421,14 @@ def test_respond_to_disable_extension
       end
 
       def test_statement_closed
-        db = SQLite3::Database.new(ActiveRecord::Base.
+        db = ::SQLite3::Database.new(ActiveRecord::Base.
                                    configurations['arunit']['database'])
-        statement = SQLite3::Statement.new(db,
+        statement = ::SQLite3::Statement.new(db,
                                            'CREATE TABLE statement_test (number integer not null)')
-        statement.stubs(:step).raises(SQLite3::BusyException, 'busy')
+        statement.stubs(:step).raises(::SQLite3::BusyException, 'busy')
         statement.stubs(:columns).once.returns([])
         statement.expects(:close).once
-        SQLite3::Statement.stubs(:new).returns(statement)
+        ::SQLite3::Statement.stubs(:new).returns(statement)
 
         assert_raises ActiveRecord::StatementInvalid do
           @conn.exec_query 'select * from statement_test'

activerecord/test/cases/test_case.rb

@@ -81,7 +81,7 @@ def clear_log; self.log = []; self.log_all = []; end
     oracle_ignored     = [/^select .*nextval/i, /^SAVEPOINT/, /^ROLLBACK TO/, /^\s*select .* from all_triggers/im, /^\s*select .* from all_constraints/im, /^\s*select .* from all_tab_cols/im]
     mysql_ignored      = [/^SHOW TABLES/i, /^SHOW FULL FIELDS/, /^SHOW CREATE TABLE /i, /^SHOW VARIABLES /]
     postgresql_ignored = [/^\s*select\b.*\bfrom\b.*pg_namespace\b/im, /^\s*select tablename\b.*from pg_tables\b/im, /^\s*select\b.*\battname\b.*\bfrom\b.*\bpg_attribute\b/im, /^SHOW search_path/i]
-    sqlite3_ignored =    [/^\s*SELECT name\b.*\bFROM sqlite_master/im]
+    sqlite3_ignored =    [/^\s*SELECT name\b.*\bFROM sqlite_master/im, /^\s*SELECT sql\b.*\bFROM sqlite_master/im]
 
     [oracle_ignored, mysql_ignored, postgresql_ignored, sqlite3_ignored].each do |db_ignored_sql|
       ignored_sql.concat db_ignored_sql