drop mysql support and gem

test plan
 - specs should pass

Change-Id: Ib3f102b53d947198625e3118820d22e77a005dd6
Reviewed-on: https://gerrit.instructure.com/77249
Reviewed-by: Cody Cutrer <cody@instructure.com>
Tested-by: Jenkins
Product-Review: Rob Orton <rob@instructure.com>
QA-Review: Rob Orton <rob@instructure.com>

Author: roor0

Gemfile.d/mysql.rb

@@ -382,7 +382,7 @@ def to_row(format = nil)
     export_columns(format).map { |c| self.send(c).presence }
   end
 
-  # utility class to migrate a postgresql/mysql/sqlite3 page_views table to cassandra
+  # utility class to migrate a postgresql/sqlite3 page_views table to cassandra
   class CassandraMigrator < Struct.new(:start_at, :logger, :migration_data)
     # if you interrupt and re-start the migrator, start_at cannot be changed,
     # since it's saved in cassandra to persist the migration state

app/models/page_view.rb

@@ -138,11 +138,7 @@ def send_confirmation!
   }
 
   def self.to_lower_column(column)
-    if %w{mysql mysql2}.include?(connection_pool.spec.config[:adapter])
-      column
-    else
-      "LOWER(#{column})"
-    end
+    "LOWER(#{column})"
   end
 
   def self.custom_find_by_unique_id(unique_id)

app/models/pseudonym.rb

@@ -428,8 +428,6 @@ def update_quiz_submission_end_at_times
     update_sql = case ActiveRecord::Base.connection.adapter_name
                  when 'PostgreSQL'
                    "started_at + INTERVAL '+? seconds'"
-                 when 'MySQL', 'Mysql2'
-                   "started_at + INTERVAL ? SECOND"
                  when /sqlite/
                    "DATETIME(started_at, '+? seconds')"
                  end

app/models/quizzes/quiz.rb

@@ -389,10 +389,6 @@ def self.count_by_date(options = {})
     offset = max_date.utc_offset
 
     expression = case connection.adapter_name
-    when 'MySQL', 'Mysql2'
-      # TODO: detect mysql named timezone support and use it
-      offset = "%s%02d:%02d" % [offset < 0 ? "-" : "+", offset.abs / 3600, offset.abs % 3600]
-      "DATE(CONVERT_TZ(#{column}, '+00:00', '#{offset}'))"
     when /sqlite/
       "DATE(STRFTIME('%s', #{column}) + #{offset}, 'unixepoch')"
     when 'PostgreSQL'
@@ -773,10 +769,6 @@ def find_in_batches_with_temp_table(options = {})
           ensure
             connection.raw_connection.set_notice_processor(&old_proc) if old_proc
           end
-        when 'MySQL', 'Mysql2'
-          pluck.unshift(index) if pluck
-          connection.execute "ALTER TABLE #{table}
-                             ADD temp_primary_key MEDIUMINT NOT NULL PRIMARY KEY AUTO_INCREMENT"
         when 'SQLite'
           # Sqlite always has an implicit primary key
           index = 'rowid'
@@ -820,8 +812,7 @@ def find_in_batches_with_temp_table(options = {})
       end
     ensure
       unless $!.is_a?(ActiveRecord::StatementInvalid)
-        temporary = "TEMPORARY " if connection.adapter_name == 'Mysql2'
-        connection.execute "DROP #{temporary}TABLE #{table}"
+        connection.execute "DROP TABLE #{table}"
       end
     end
   end
@@ -1012,8 +1003,6 @@ def delete_all(conditions = nil, *args)
               end
               sql.concat('WHERE ' + sql_string.compile(binds.map{|bvs| connection.quote(*bvs.reverse)}))
             end
-          when 'MySQL', 'Mysql2'
-            sql = "DELETE #{quoted_table_name} FROM #{quoted_table_name} #{arel.join_sql} #{arel.where_sql}"
           else
             raise "Joins in delete not supported!"
         end
@@ -1103,57 +1092,6 @@ def infer_group_by_columns(columns)
   end
 end
 
-module MySQLAdapterExtensions
-  def self.included(klass)
-    klass::NATIVE_DATABASE_TYPES[:primary_key] = "bigint DEFAULT NULL auto_increment PRIMARY KEY".freeze
-    klass.alias_method_chain :configure_connection, :pg_compat
-  end
-
-  def rename_index(table_name, old_name, new_name)
-    if version[0] >= 5 && version[1] >= 7
-      return execute "ALTER TABLE #{quote_table_name(table_name)} RENAME INDEX #{quote_column_name(old_name)} TO #{quote_table_name(new_name)}";
-    else
-      old_index_def = indexes(table_name).detect { |i| i.name == old_name }
-      return unless old_index_def
-      add_index(table_name, old_index_def.columns, :name => new_name, :unique => old_index_def.unique)
-      remove_index(table_name, :name => old_name)
-    end
-  end
-
-  def bulk_insert(table_name, records)
-    keys = records.first.keys
-    quoted_keys = keys.map{ |k| quote_column_name(k) }.join(', ')
-    execute "INSERT INTO #{quote_table_name(table_name)} (#{quoted_keys}) VALUES" <<
-                records.map{ |record| "(#{keys.map{ |k| quote(record[k]) }.join(', ')})" }.join(',')
-  end
-
-  def add_column_with_foreign_key_check(table, name, type, options = {})
-    Canvas.active_record_foreign_key_check(name, type, options) unless adapter_name == 'Sqlite'
-    add_column_without_foreign_key_check(table, name, type, options)
-  end
-
-  def configure_connection_with_pg_compat
-    configure_connection_without_pg_compat
-    execute "SET SESSION SQL_MODE='PIPES_AS_CONCAT'"
-  end
-
-  def func(name, *args)
-    case name
-      when :group_concat
-        "group_concat(#{func_arg_esc(args.first)} SEPARATOR #{quote(args[1] || ',')})"
-      else
-        super
-    end
-  end
-end
-
-if defined?(ActiveRecord::ConnectionAdapters::MysqlAdapter)
-  ActiveRecord::ConnectionAdapters::MysqlAdapter.send(:include, MySQLAdapterExtensions)
-end
-if defined?(ActiveRecord::ConnectionAdapters::Mysql2Adapter)
-  ActiveRecord::ConnectionAdapters::Mysql2Adapter.send(:include, MySQLAdapterExtensions)
-end
-
 ActiveRecord::Associations::HasOneAssociation.class_eval do
   def create_scope
     scope = self.scope.scope_for_create.stringify_keys
@@ -1330,7 +1268,7 @@ def remove_foreign_key_if_exists(table, options = {})
     begin
       remove_foreign_key(table, options)
     rescue ActiveRecord::StatementInvalid => e
-      raise unless e.message =~ /PG(?:::)?Error: ERROR:.+does not exist|Mysql2?::Error: Error on rename/
+      raise unless e.message =~ /PG(?:::)?Error: ERROR:.+does not exist/
     end
   end
 

config/initializers/active_record.rb

@@ -12,14 +12,11 @@ def self.up
 
     return if Rails.env.test?
 
-    unless connection.adapter_name =~ /postgres|mysql/i
+    unless connection.adapter_name =~ /postgres/
       $stderr.puts "don't know how to migrate conversation data for #{connection.adapter_name}!"
       return
     end
 
-    mysql = %w{MySQL Mysql2}.include?(connection.adapter_name)
-    table_opts = mysql ? 'engine=innodb' : 'AS'
-
     # for grouping messages into conversations
     #   private: list of participant ids <= 2
     #   group: root_context_message_id + list of participant ids (if the list changes, it's a different conversation)
@@ -32,7 +29,7 @@ def self.up
     add_column :conversation_message_participants, :unread, :boolean
 
     execute <<-SQL
-      CREATE TEMPORARY TABLE __migrated_messages #{table_opts}
+      CREATE TEMPORARY TABLE __migrated_messages AS
       SELECT
         id,
         user_id AS author_id,
@@ -41,15 +38,14 @@ def self.up
         COALESCE(root_context_message_id, id) AS root_context_message_id,
         media_comment_id,
         media_comment_type,
-        ''#{mysql ? '' : '::TEXT'} AS signature
+        '::TEXT' AS signature
       FROM
         #{connection.quote_table_name('context_messages')}
     SQL
-    change_column :__migrated_messages, :signature, :text if mysql
     execute "CREATE INDEX index__migrated_messages_on_id ON __migrated_messages (id)"
 
     execute <<-SQL
-      CREATE TEMPORARY TABLE __migrated_message_participants #{table_opts}
+      CREATE TEMPORARY TABLE __migrated_message_participants AS
       SELECT DISTINCT
         context_message_id AS migrated_message_id,
         user_id
@@ -58,72 +54,47 @@ def self.up
     SQL
     execute "CREATE INDEX index_mmp_on_message_id ON __migrated_message_participants (migrated_message_id)"
 
-    if mysql
-      execute  <<-SQL
-        CREATE TEMPORARY TABLE __migrated_message_participant_strings #{table_opts}
-        SELECT migrated_message_id, GROUP_CONCAT(DISTINCT user_id ORDER BY user_id) AS participants, COUNT(DISTINCT user_id) <= 2 AS private
+    execute <<-SQL
+      CREATE TEMPORARY TABLE __migrated_message_participant_strings AS
+      SELECT migrated_message_id, STRING_AGG(user_id::TEXT, ',') AS participants, COUNT(DISTINCT user_id) <= 2 AS private
+      FROM (
+        SELECT DISTINCT migrated_message_id, user_id
         FROM __migrated_message_participants
-        GROUP BY migrated_message_id
-      SQL
-    else
-      execute <<-SQL
-        CREATE TEMPORARY TABLE __migrated_message_participant_strings #{table_opts}
-        SELECT migrated_message_id, STRING_AGG(user_id::TEXT, ',') AS participants, COUNT(DISTINCT user_id) <= 2 AS private
-        FROM (
-          SELECT DISTINCT migrated_message_id, user_id
-          FROM __migrated_message_participants
-          ORDER BY migrated_message_id, user_id
-        ) p
-        GROUP BY migrated_message_id
-      SQL
-    end
+        ORDER BY migrated_message_id, user_id
+      ) p
+      GROUP BY migrated_message_id
+    SQL
     execute "CREATE INDEX index_mmps_on_migrated_message_id ON __migrated_message_participant_strings (migrated_message_id)"
 
     execute <<-SQL
-      UPDATE __migrated_messages #{mysql ? ", __migrated_message_participant_strings" : ""}
+      UPDATE __migrated_messages
       SET signature = CASE WHEN private THEN '' ELSE root_context_message_id || ':' END || participants
-      #{mysql ? "" : " FROM __migrated_message_participant_strings"}
+      FROM __migrated_message_participant_strings
       WHERE migrated_message_id = __migrated_messages.id
     SQL
-    if mysql
-      execute "CREATE INDEX index___migrated_messages_on_signature ON __migrated_messages (signature(767))"
-    else
-      execute "CREATE INDEX index___migrated_messages_on_signature ON __migrated_messages (signature)"
-    end
+    execute "CREATE INDEX index___migrated_messages_on_signature ON __migrated_messages (signature)"
 
     execute <<-SQL
       INSERT INTO #{Conversation.quoted_table_name}(migration_signature, has_attachments, has_media_objects)
       SELECT DISTINCT signature, FALSE, FALSE
       FROM __migrated_messages
     SQL
-    if mysql
-      execute "CREATE INDEX index_conversations_on_migration_signature ON conversations (migration_signature(767))"
-    else
-      add_index :conversations, :migration_signature
-    end
+    add_index :conversations, :migration_signature
 
-    if mysql
-      update <<-SQL
-        UPDATE #{Conversation.quoted_table_name}
-        SET tmp_private_hash = SHA(migration_signature)
-        WHERE migration_signature REGEXP '^[0-9]+(,[0-9]+)?$'
-      SQL
-    else
-      Conversation.where("migration_signature ~ E'^[0-9]+(,[0-9]+)?$'").find_each(:batch_size => 10000) do |conversation|
-        conversation.update_attribute :tmp_private_hash, Digest::SHA1.hexdigest(conversation.migration_signature)
-      end
+    Conversation.where("migration_signature ~ E'^[0-9]+(,[0-9]+)?$'").find_each(:batch_size => 10000) do |conversation|
+      conversation.update_attribute :tmp_private_hash, Digest::SHA1.hexdigest(conversation.migration_signature)
     end
     add_index :conversations, :tmp_private_hash
 
     # in case any private conversations already exist...
     update <<-SQL
-      UPDATE #{Conversation.quoted_table_name} #{mysql ? ", #{Conversation.quoted_table_name} c2" : ""}
-      SET #{mysql ? "conversations." : ""}migration_signature = c2.migration_signature
-      #{mysql ? "" : " FROM #{Conversation.quoted_table_name} c2"}
+      UPDATE #{Conversation.quoted_table_name}
+      SET migration_signature = c2.migration_signature
+      FROM #{Conversation.quoted_table_name} c2
       WHERE conversations.private_hash = c2.tmp_private_hash
     SQL
     execute <<-SQL
-      CREATE TEMPORARY TABLE __existing_private_conversations #{table_opts}
+      CREATE TEMPORARY TABLE __existing_private_conversations AS
       SELECT private_hash FROM #{Conversation.quoted_table_name} WHERE private_hash IS NOT NULL
     SQL
     delete <<-SQL
@@ -133,9 +104,7 @@ def self.up
     # create participants for any group conversations or *new* private conversations
     remove_index :conversation_participants, :column => [:user_id, :last_message_at]
     add_index :conversation_participants, :user_id # temporary for better insert speeds (and to prevent people hitting new messaging from killing the db)
-    subquery = mysql ?
-      "SELECT signature, id FROM __migrated_messages GROUP BY signature ORDER BY signature, id DESC" :
-      "SELECT DISTINCT ON (signature) signature, id FROM __migrated_messages ORDER BY signature, id DESC"
+    subquery = "SELECT DISTINCT ON (signature) signature, id FROM __migrated_messages ORDER BY signature, id DESC"
     execute <<-SQL
       INSERT INTO #{ConversationParticipant.quoted_table_name}(conversation_id, user_id, subscribed, workflow_state, has_attachments, has_media_objects)
       SELECT c.id, mp.user_id, TRUE, 'read', FALSE, FALSE
@@ -222,9 +191,9 @@ def self.up
 
     # attachments
     update <<-SQL
-      UPDATE #{Attachment.quoted_table_name} #{mysql ? ', conversation_messages' : ''}
+      UPDATE #{Attachment.quoted_table_name}
       SET context_id = conversation_messages.id, context_type = 'ConversationMessage'
-      #{mysql ? '' : "FROM #{ConversationMessage.quoted_table_name}"}
+      FROM #{ConversationMessage.quoted_table_name}
       WHERE attachments.context_type = 'ContextMessage' AND conversation_messages.context_message_id = attachments.context_id
     SQL
 
@@ -276,7 +245,7 @@ def self.up
 
     # cached stats
     execute <<-SQL
-      CREATE TEMPORARY TABLE __migrated_conversation_stats #{table_opts}
+      CREATE TEMPORARY TABLE __migrated_conversation_stats AS
       SELECT
         conversation_participant_id,
         COUNT(*) AS message_count,
@@ -289,36 +258,20 @@ def self.up
     execute "CREATE INDEX index_mcs_on_cpi ON __migrated_conversation_stats (conversation_participant_id)"
 
     update <<-SQL
-      UPDATE #{ConversationParticipant.quoted_table_name} #{mysql ? ', __migrated_conversation_stats' : ''}
-      SET #{mysql ? 'conversation_participants.' : ''}message_count = __migrated_conversation_stats.message_count,
-        #{mysql ? 'conversation_participants.' : ''}last_message_at = __migrated_conversation_stats.last_message_at,
-        #{mysql ? 'conversation_participants.' : ''}last_authored_at = __migrated_conversation_stats.last_authored_at
-      #{mysql ? '' : 'FROM __migrated_conversation_stats'}
+      UPDATE #{ConversationParticipant.quoted_table_name}
+      SET message_count = __migrated_conversation_stats.message_count,
+        last_message_at = __migrated_conversation_stats.last_message_at,
+        last_authored_at = __migrated_conversation_stats.last_authored_at
+      'FROM __migrated_conversation_stats'
       WHERE conversation_participants.id = conversation_participant_id
     SQL
-    if mysql
-      execute <<-SQL
-        ALTER TABLE #{ConversationParticipant.quoted_table_name}
-        ADD INDEX index_conversation_participants_on_user_id_and_last_message_at (user_id, last_message_at),
-        DROP INDEX index_conversation_participants_on_user_id
-      SQL
-    else
-      add_index :conversation_participants, [:user_id, :last_message_at]
-      remove_index :conversation_participants, :column => :user_id
-    end
+    add_index :conversation_participants, [:user_id, :last_message_at]
+    remove_index :conversation_participants, :column => :user_id
 
-    if mysql
-      update <<-SQL
-        UPDATE #{User.quoted_table_name}, (SELECT COUNT(*) AS unread_count, user_id FROM #{ConversationParticipant.quoted_table_name} WHERE workflow_state = 'unread' GROUP BY user_id) AS counts
-        SET unread_conversations_count = unread_count
-        WHERE user_id = users.id
-      SQL
-    else
-      execute <<-SQL
-        UPDATE #{User.quoted_table_name}
-        SET unread_conversations_count = (SELECT COUNT(*) FROM #{ConversationParticipant.quoted_table_name} WHERE workflow_state = 'unread' AND user_id = users.id)
-      SQL
-    end
+    execute <<-SQL
+      UPDATE #{User.quoted_table_name}
+      SET unread_conversations_count = (SELECT COUNT(*) FROM #{ConversationParticipant.quoted_table_name} WHERE workflow_state = 'unread' AND user_id = users.id)
+    SQL
 
     remove_column :conversations, :migration_signature
     remove_column :conversations, :tmp_private_hash

db/migrate/20110816203511_message_migration.rb

@@ -9,10 +9,6 @@ def self.up
   def self.down
     add_column :pseudonyms, :deleted_unique_id, :string
     Pseudonym.where("unique_id IS NOT NULL AND workflow_state='deleted'").update_all('deleted_unique_id=unique_id')
-    if %w{MySQL Mysql2}.include?(Pseudonym.connection.adapter_name)
-      Pseudonym.where("unique_id IS NOT NULL AND workflow_state='deleted'").update_all("unique_id=unique_id || '--' || SUBSTR(RAND(), 3, 4)")
-    else
-      Pseudonym.where("unique_id IS NOT NULL AND workflow_state='deleted'").update_all("unique_id=unique_id || '--' || SUBSTR(CAST(RANDOM() AS varchar), 3, 4)")
-    end
+    Pseudonym.where("unique_id IS NOT NULL AND workflow_state='deleted'").update_all("unique_id=unique_id || '--' || SUBSTR(CAST(RANDOM() AS varchar), 3, 4)")
   end
 end