In Oracle you can use LISTAGG function to concatenate strings from multiple rows into a single row value. In PostgreSQL you can use STRING_AGG function.
Consider a sample table:
CREATE TABLE cities (name VARCHAR(30)); -- Insert sample rows INSERT INTO cities VALUES ('Seville'); INSERT INTO cities VALUES ('Warsaw'); INSERT INTO cities VALUES ('Boston');
Oracle:
-- Concatenate values using ';' delimiter SELECT LISTAGG(name, ';') WITHIN GROUP (ORDER BY name) FROM cities; # Boston;Seville;Warsaw
PostgreSQL:
-- Concatenate values using ';' delimiter SELECT STRING_AGG(name, ';' ORDER BY name) FROM cities; # Boston;Seville;Warsaw
For more information, see Oracle to PostgreSQL Migration.