-- если НЕ менять порядок столбцов и не удалять столбцы
ALTER TABLE B
  RENAME TO old_B;

select * into B fom A;

insert B
select * from old_B;

drop table old_B;

-- если НЕ менять порядок столбцов и не удалять столбцы
ALTER TABLE B
  RENAME TO old_B;

select * into B fom A;

insert B
select * from old_B;

drop table old_B;

ALTER TABLE B
  RENAME TO old_B;

sp_rename

select
	case when a.TABLE_NAME is null
	then
		'alter table '+a.TABLE_SCHEMA+'.'+a.TABLE_NAME+
		' add '+b.COLUMN_NAME+' '+b.DATA_TYPE+isnull('('+b.CHARACTER_MAXIMUM_LENGTH+')','')
		+isnull('('+b.NUMERIC_PRECISION+','+b.NUMERIC_SCALE+')','')
	else
		'alter table '+a.TABLE_SCHEMA+'.'+a.TABLE_NAME+
		' drop column '+a.COLUMN_NAME+';'
	end
	,*
from	INFORMATION_SCHEMA.columns a
full join
		INFORMATION_SCHEMA.columns b
	on a.TABLE_CATALOG=b.TABLE_CATALOG
	and a.TABLE_SCHEMA=b.TABLE_SCHEMA
	and a.TABLE_NAME = b.TABLE_NAME
where	a.TABLE_NAME = 'SourceTable'
	and	b.TABLE_NAME = 'DestTable'
	and	(
		a.TABLE_NAME is null
	or	b.TABLE_NAME is null
		)