數據庫 批量查詢結果作爲更新的值

1. 數據庫批量更新。

業務需求：

需要將a表中 type爲1 的數據的source_id更新爲新的id。

因爲之前的id是存儲在p_server中，現在更新到了server_info表中

update a set source_id = s.server_id  from 
(select p_server.p_id,p_server.index_code,server_info.server_id 
from p_server join server_info 
on p_server.index_code = server_info.index_code) s where 
a.source_id = s.p_id
and type = 1;

2. 更新數據庫中的值，但是這些值存在不同的表中

CREATE OR REPLACE FUNCTION replace_img_url()
  RETURNS SETOF refcursor AS
$BODY$ 
DECLARE _ss_urls record;	
updateVehicle "varchar" := '';	
updateImage "varchar" := '';
ss_ip "varchar" := '';  
BEGIN          
for _ss_urls IN EXECUTE 'select svr_id as server_id,svr_ip||'':''||substring(svr_config,E''<httpPort>([0-9]*)?'') as url from server_multi_ip where svr_type = 20002'	loop 
   updateImage := 'update alarm_image set image_url = tep.url from (select alarm_event_id as event_id,time_happen,rule_id,sort_num, 
   replace(image_url, '''||_ss_urls.url||''','''||_ss_urls.server_id||''') as url from alarm_image) tep 
    where alarm_image.time_happen = tep.time_happen and alarm_image.alarm_event_id = tep.event_id and alarm_image.rule_id = tep.rule_id and alarm_image.sort_num = tep.sort_num';	   
  execute updateImage;	   

   updateVehicle :='update vehicle_recognition set vehicle_image_url = tep.url from (select vehicle_recog_id as id,vehicle_recog_id, replace(vehicle_image_url, '''||_ss_urls.url||''',
    '''||_ss_urls.server_id||''') as url from vehicle_recognition) tep where vehicle_recognition.vehicle_recog_id = tep.id';       
  execute updateVehicle;	    	
  end loop;   
 END;  $BODY$
  LANGUAGE plpgsql VOLATILE
  COST 100
  ROWS 1000;
ALTER FUNCTION replace_img_url() OWNER TO postgres;