In SQL Server and PostgreSQL, the SUBSTRING function returns the substring.
SQL Server:
-- Get substring starting at position 2 and length 3 SELECT SUBSTRING('abcde', 2, 3); # bcd
PostgreSQL:
-- Get substring starting at position 2 and length 3 SELECT SUBSTRING('abcde', 2, 3); # bcd
For more information, see SQL Server to PostgreSQL Migration.