How To Create A Cursor

declare @Script_Code nvarchar(400),@Script_Name nvarchar(400),@rownum nvarchar(400)

declare @Script_Code1 nvarchar(400),@Script_Name1  nvarchar(400)

declare @Counter int

set @Counter=0

DECLARE db_cursor CURSOR FOR 

select shareName,ShareCode,rownum

 from (

select  distinct row_number() over (order by ShareCode asc) as rownum, shareName,ShareCode from Table_3 )Temp

order by rownum asc 

OPEN db_cursor  

FETCH NEXT FROM db_cursor INTO @Script_Code,@Script_Name,@rownum

WHILE @@FETCH_STATUS = 0  

BEGIN  

print @Counter

update Test1 set Script_Name=UPPER(@Script_Name) where Script_Code=@Script_Code

print @Script_Code

set @Counter=@Counter+1

print @Counter

FETCH NEXT FROM db_cursor INTO @Script_Code,@Script_Name,@rownum

END  

CLOSE db_cursor  

DEALLOCATE db_cursor