mssql批量增加主键

DBCC FREEPROCCACHE  -- 清空执行计划缓存
DECLARE @couName int,  @tableName NVARCHAR(50),@sql NVARCHAR(150),@sql1 NVARCHAR(200)   --声明变量，需要读取的数据
DECLARE cur CURSOR	static		--声明静态游标

FOR
    select Name From SysObjects  Where xtype='U';
OPEN cur								--打开游标
FETCH NEXT FROM cur INTO @tableName     --取数据
WHILE ( @@fetch_status = 0 )            --判断是否还有数据
    BEGIN
	   set  @sql ='select @couName =  COUNT(*)  from dbo.sysobjects where xtype=''PK'' and parent_obj=(select id from dbo.sysobjects where name=@tableName )';
	   EXEC sp_executesql @sql,N'@couName int output, @tableName NVARCHAR(50)' ,@couName output,   @tableName;
	   select @tableName as "表名"
	   if(@couName > 0)
	   BEGIN
			  select  @tableName  as 表名,@couName as 主键
	   END
	   else
	   BEGIN
			if(@tableName != 'wmanage' and @tableName != 'strategy' and @tableName !='strain_para')
			begin
			 print('ALTER TABLE "'+ @tableName+ '" ADD pk_id int   NOT NULL IDENTITY (1,1), CONSTRAINT PK_'+@tableName+' PRIMARY KEY CLUSTERED (pk_id)')
			 exec('ALTER TABLE "'+ @tableName+ '" ADD pk_id   int NOT NULL IDENTITY (1,1), CONSTRAINT  "PK_'+@tableName+'" PRIMARY KEY CLUSTERED (pk_id)')
			-- print('ALTER TABLE '+ @tableName+ ' ADD pk_id int   UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY')
			-- exec('ALTER TABLE "'+ @tableName+ ' " ADD pk_id int    NOT NULL   INT NOT NULL PRIMARY KEY AUTO_INCREMENT "0"')
			-- set @sql1 = 'ALTER TABLE @tableName ADD id int identity(1,1) PRIMARY KEY'
			-- EXEC sp_executesql @sql1,N'@tableName NVARCHAR(50)',@tableName 
			end
	   END
	   FETCH NEXT FROM cur INTO @tableName   --这里一定要写取下一条数据
    END
CLOSE cur								--关闭游标
DEALLOCATE cur