mssql 返回表的创建语句

if OBJECT_ID('sp_create_table_sql','P') is not null
drop proc sp_create_table_sql
go
create proc sp_create_table_sql ( @tablename varchar(255) )
as
begin
	 -- exec sp_create_table_sql 'Ad_AdGroup'
	 -- 0. 弘恩
	 -- 1. 不支持非主键类的索引
	 -- 2. 不支持主分键的非默认排序
	 -- 3. 不支持DEFAULT
	 -- 4. 不支持计算列
	 -- 5. 待完整
	declare @sql_create varchar(max) = '';
	declare @sql_column varchar(max);
	declare @sql_primary varchar(max);

	with cte as
	(
		select  QUOTENAME( c.name )+' '+
				TYPE_NAME(c.system_type_id)+' '+
				case when  TYPE_NAME( c.system_type_id) in  ('char','varchar','decimal')  then ' ( '  else ''  end +
				case when  TYPE_NAME( c.system_type_id) in  ('char','varchar','nvarchar'  )  then cast(max_length as varchar)  else ''  end+
				case when  TYPE_NAME( c.system_type_id) in  ('decimal'  )  then cast(c.precision as varchar)+','+cast(c.scale AS varchar) else ''  end+
				case when  TYPE_NAME( c.system_type_id) in  ('char','varchar','decimal')  then ' ) ' else ''  end +
				case when c.is_nullable = 1 then ' null ' else ' not null ' end +
				case when c.is_identity = 0 then ' ' else ' identity ' end  sqlstr ,  

				column_id
		 from sys.objects as o
		 join sys.columns as c on o.object_id = c.object_id
		 where o.name = @tablename and o.type = 'U'
	 )
	select @sql_column = stuff(
	(select  ',' + sqlstr  + CHAR(10)
	from cte
	order by column_id asc
	for xml path('') ),1,1,'')
	 ;

	select @sql_primary = stuff((
	 select ',' + c.name
	 from sys.index_columns as i
	 join sys.indexes as ix on i.object_id = ix.object_id  and i.index_id = ix.index_id
	 join sys.columns as c on i.object_id = c.object_id  and i.column_id = c.column_id
	 where OBJECT_NAME(i.object_id) = @tablename
	 and ix.is_primary_key = 1
	  order by i.key_ordinal
	 for xml path('')
	 ),1,1,'')

	 set @sql_create = ' create table ' + @tablename + '( '
	 +   @sql_column
	 + case when len(@sql_primary) >= 1 then  (', primary key ( ' + @sql_primary + ')') else '' end
	 + ' ) '

	print ' -- @sql_create -- '
	print @sql_create
end