Revert "ask the fixture set for the sql statements"

This reverts commit 026d055568.

Conflicts:
	activerecord/lib/active_record/fixtures.rb

Fixes #13383

activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb

@@ -286,10 +286,6 @@ module ActiveRecord
       # Inserts the given fixture into the table. Overridden in adapters that require
       # something beyond a simple insert (eg. Oracle).
       def insert_fixture(fixture, table_name)
-        execute fixture_sql(fixture, table_name), 'Fixture Insert'
-      end
-
-      def fixture_sql(fixture, table_name)
         columns = schema_cache.columns_hash(table_name)
 
         key_list   = []
@@ -298,7 +294,7 @@ module ActiveRecord
           quote(value, columns[name])
         end
 
-        "INSERT INTO #{quote_table_name(table_name)} (#{key_list.join(', ')}) VALUES (#{value_list.join(', ')})"
+        execute "INSERT INTO #{quote_table_name(table_name)} (#{key_list.join(', ')}) VALUES (#{value_list.join(', ')})", 'Fixture Insert'
       end
 
       def empty_insert_statement_value

activerecord/lib/active_record/fixtures.rb

@@ -521,8 +521,16 @@ module ActiveRecord
           connection.transaction(:requires_new => true) do
             fixture_sets.each do |fs|
               conn = fs.model_class.respond_to?(:connection) ? fs.model_class.connection : connection
-              fs.fixture_sql(conn).each do |stmt|
-                conn.execute stmt
+              table_rows = fs.table_rows
+
+              table_rows.keys.each do |table|
+                conn.delete "DELETE FROM #{conn.quote_table_name(table)}", 'Fixture Delete'
+              end
+
+              table_rows.each do |fixture_set_name, rows|
+                rows.each do |row|
+                  conn.insert_fixture(row, fixture_set_name)
+                end
               end
             end
 
@@ -594,16 +602,6 @@ module ActiveRecord
       fixtures.size
     end
 
-    def fixture_sql(conn)
-      table_rows = self.table_rows
-
-      table_rows.keys.map { |table|
-        "DELETE FROM #{conn.quote_table_name(table)}"
-      }.concat table_rows.flat_map { |fixture_set_name, rows|
-        rows.map { |row| conn.fixture_sql(row, fixture_set_name) }
-      }
-    end
-
     # Returns a hash of rows to be inserted. The key is the table, the value is
     # a list of rows to insert to that table.
     def table_rows