نمایش نتایج پرس‌و‌جوها به صورت یک مقدار جداشده با کاما در Oracle

1SELECT region_name
2FROM regions;

1REGION_NAME
2------------------------
3Americas                  
4Asia                      
5Middle East and Africa  

1SELECT LISTAGG(region_name, ', ')
2FROM regions;

1LISTAGG(LAST_NAME,',') 
2-----------------------------------------------
3Europe, Americas, Asia, Middle East and Africa      

1SELECT LISTAGG(DISTINCT region_id, ',') 
2FROM countries

1LISTAGG(DISTINCT region_id, ',') 
2--------------------------------------------
31,2,3,4

1SELECT LISTAGG(region_name, ',') WITHIN GROUP (ORDER BY region_name ASC) 
2FROM regions;

1LISTAGG(region_name, ',')
2--------------------------------------------
3Americas,Asia,Europe,Middle East and Africa

1SELECT 
2    region_id,
3    LISTAGG(country_id, ', ') WITHIN GROUP (ORDER BY country_id ASC) AS "Countries"
4FROM countries
5GROUP BY region_id
6ORDER BY region_id;

1REGION_ID	Countries 
2------------------------------------------------
31		BE, CH, DE, DK, FR, IT, NL, UK    
42		AR, BR, CA, MX, US                
53		AU, CN, HK, IN, JP, SG            
64		EG, IL, KW, NG, ZM, ZW