How can I combine multiple rows into a comma-delimited list in Oracle? [duplicate]

The WM_CONCAT function (if included in your database, pre Oracle 11.2) or LISTAGG (starting Oracle 11.2) should do the trick nicely. For example, this gets a comma-delimited list of the table names in your schema:

select listagg(table_name, ', ') within group (order by table_name)   from user_tables;

or

select wm_concat(table_name)   from user_tables;

More details/options

Link to documentation

Here is a simple way without stragg or creating a function.

create table countries ( country_name varchar2 (100));insert into countries values ('Albania');insert into countries values ('Andorra');insert into countries values ('Antigua');SELECT SUBSTR (SYS_CONNECT_BY_PATH (country_name , ','), 2) csv      FROM (SELECT country_name , ROW_NUMBER () OVER (ORDER BY country_name ) rn,                   COUNT (*) OVER () cnt              FROM countries)     WHERE rn = cntSTART WITH rn = 1CONNECT BY rn = PRIOR rn + 1;CSV                                                                             --------------------------Albania,Andorra,Antigua                                                         1 row selected.

As others have mentioned, if you are on 11g R2 or greater, you can now use listagg which is much simpler.

select listagg(country_name,', ') within group(order by country_name) csv  from countries;CSV                                                                             --------------------------Albania, Andorra, Antigua1 row selected.

You can use this as well:

SELECT RTRIM (          XMLAGG (XMLELEMENT (e, country_name || ',')).EXTRACT ('//text()'),          ',')          country_name  FROM countries;