PostgreSQL/Sequence/Currval

Using currval function to get sequence current value

postgres=#
postgres=#
postgres=# CREATE SEQUENCE myseq MINVALUE 0;
CREATE SEQUENCE
postgres=#
postgres=# -- Using currval(?)
postgres=#
postgres=# SELECT currval("myseq");
ERROR:  currval of sequence "myseq" is not yet defined in this session
postgres=#
postgres=#
postgres=# drop sequence myseq;
DROP SEQUENCE
postgres=#
postgres=# -- Setting a sequence value
postgres=# CREATE SEQUENCE myseq MINVALUE 0;
CREATE SEQUENCE
postgres=#
postgres=# SELECT setval("myseq", 1010);
 setval
--------
   1010
(1 row)
postgres=#
postgres=# SELECT nextval("myseq");
 nextval
---------
    1011
(1 row)
postgres=#
postgres=#
postgres=# SELECT setval("myseq", 1010, false);
 setval
--------
   1010
(1 row)
postgres=#
postgres=# SELECT nextval("myseq");
 nextval
---------
    1010
(1 row)
postgres=#
postgres=# drop sequence myseq;
DROP SEQUENCE
postgres=#