text: DROP TABLE IF EXISTS alter;
  CREATE TABLE alter (`boolean_false` Nullable(String)) ENGINE = MergeTree ORDER BY tuple();
  
  INSERT INTO alter (`boolean_false`) VALUES (NULL), (''), ('123');
  SELECT * FROM alter;
  SELECT * FROM alter ORDER BY boolean_false NULLS LAST;
  
  ALTER TABLE alter MODIFY COLUMN `boolean_false` Nullable(UInt8);
  SELECT * FROM alter;
  SELECT * FROM alter ORDER BY boolean_false NULLS LAST;
  
  DROP TABLE alter;
  