1 files changed, 32 insertions, 24 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/mysql/schema_dumper.rb b/activerecord/lib/active_record/connection_adapters/mysql/schema_dumper.rb
index 3e0afd9761..d23178e43c 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql/schema_dumper.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql/schema_dumper.rb
@@ -1,25 +1,29 @@
+# frozen_string_literal: true
+
 module ActiveRecord
   module ConnectionAdapters
     module MySQL
-      module ColumnDumper # :nodoc:
-        def prepare_column_options(column)
-          spec = super
-          spec[:unsigned] = "true" if column.unsigned?
-
-          if supports_virtual_columns? && column.virtual?
-            spec[:as] = extract_expression_for_virtual_column(column)
-            spec[:stored] = "true" if /\b(?:STORED|PERSISTENT)\b/.match?(column.extra)
-            spec = { type: schema_type(column).inspect }.merge!(spec)
-          end
+      class SchemaDumper < ConnectionAdapters::SchemaDumper # :nodoc:
+        private
+          def prepare_column_options(column)
+            spec = super
+            spec[:unsigned] = "true" if column.unsigned?
+            spec[:auto_increment] = "true" if column.auto_increment?
 
-          spec
-        end
+            if @connection.supports_virtual_columns? && column.virtual?
+              spec[:as] = extract_expression_for_virtual_column(column)
+              spec[:stored] = "true" if /\b(?:STORED|PERSISTENT)\b/.match?(column.extra)
+              spec = { type: schema_type(column).inspect }.merge!(spec)
+            end
 
-        def migration_keys
-          super + [:unsigned]
-        end
+            spec
+          end
 
-        private
+          def column_spec_for_primary_key(column)
+            spec = super
+            spec.delete(:auto_increment) if column.type == :integer && column.auto_increment?
+            spec
+          end
 
           def default_primary_key?(column)
             super && column.auto_increment? && !column.unsigned?
@@ -47,23 +51,27 @@ module ActiveRecord
           def schema_collation(column)
             if column.collation && table_name = column.table_name
               @table_collation_cache ||= {}
-              @table_collation_cache[table_name] ||= select_one("SHOW TABLE STATUS LIKE '#{table_name}'")["Collation"]
+              @table_collation_cache[table_name] ||=
+                @connection.exec_query("SHOW TABLE STATUS LIKE #{@connection.quote(table_name)}", "SCHEMA").first["Collation"]
               column.collation.inspect if column.collation != @table_collation_cache[table_name]
             end
           end
 
           def extract_expression_for_virtual_column(column)
-            if mariadb?
-              create_table_info = create_table_info(column.table_name)
-              if %r/#{quote_column_name(column.name)} #{Regexp.quote(column.sql_type)} AS \((?<expression>.+?)\) #{column.extra}/m =~ create_table_info
+            if @connection.mariadb? && @connection.version < "10.2.5"
+              create_table_info = @connection.send(:create_table_info, column.table_name)
+              column_name = @connection.quote_column_name(column.name)
+              if %r/#{column_name} #{Regexp.quote(column.sql_type)}(?: COLLATE \w+)? AS \((?<expression>.+?)\) #{column.extra}/ =~ create_table_info
                 $~[:expression].inspect
               end
             else
+              scope = @connection.send(:quoted_scope, column.table_name)
+              column_name = @connection.quote(column.name)
               sql = "SELECT generation_expression FROM information_schema.columns" \
-                    " WHERE table_schema = #{quote(@config[:database])}" \
-                    "   AND table_name = #{quote(column.table_name)}" \
-                    "   AND column_name = #{quote(column.name)}"
-              select_value(sql, "SCHEMA").inspect
+                    " WHERE table_schema = #{scope[:schema]}" \
+                    "   AND table_name = #{scope[:name]}" \
+                    "   AND column_name = #{column_name}"
+              @connection.query_value(sql, "SCHEMA").inspect
             end
           end
       end