I am trying to loop through the records in a table and update a column. I can do this with a case statement but I would like to simplify this to a simple loop statement. I can´t seem to work out how to do it though.
Here is the case statement.
select name,ges_kw_zgb,
case
When name='Bad Harzburg' then (select round(100 * (ges_kw_zgb / (select sum(ges_kw_zgb) From energie.tennet_auswertung_2010)),2))
When name='Braunlage' then (select round(100 * (ges_kw_zgb / (select sum(ges_kw_zgb) From energie.tennet_auswertung_2010)),2))
When name='Braunschweig' then (select round(100 * (ges_kw_zgb / (select sum(ges_kw_zgb) From energie.tennet_auswertung_2010)),2))
When name='Büddenstedt' then (select round(100 * (ges_kw_zgb / (select sum(ges_kw_zgb) From energie.tennet_auswertung_2010)),2))
End as z
from energie.tennet_auswertung_2010
;
Instead of having to write the name variable in the function, I would just like to iterate through each record and execute the select round(100 * (ges_kw_zgb / (select sum(ges_kw_zgb) From energie.tennet_auswertung_2010)),2) command.
