#THE SEQUENCES UPDATE#

This function requires USAGE or SELECT privilege on the sequence. (An error is reported if nextval has never been called for this sequence in this session.) Because this is returning a session-local value, it gives a predictable answer whether or not other sessions have executed nextval since the current session did. Returns the value most recently obtained by nextval for this sequence in the current session.

#THE SEQUENCES UPDATE#

This function requires UPDATE privilege on the sequence. The result returned by setval is just the value of its second argument. SELECT setval('myseq', 42, false) Next nextval will return 42 SELECT setval('myseq', 42, true) Same as above SELECT setval('myseq', 42) Next nextval will return 43 Furthermore, the value reported by currval is not changed in this case. If it is set to false, the next nextval will return exactly the specified value, and sequence advancement commences with the following nextval. true has the same effect as the two-parameter form. In the three-parameter form, is_called can be set to either true or false. The value that will be reported by currval is also set to the specified value. The two-parameter form sets the sequence's last_value field to the specified value and sets its is_called field to true, meaning that the next nextval will advance the sequence before returning a value.

Sets the sequence object's current value, and optionally its is_called flag. This function requires USAGE or UPDATE privilege on the sequence. Other behaviors can be obtained by using appropriate parameters in the CREATE SEQUENCE command. If the sequence object has been created with default parameters, successive nextval calls will return successive values beginning with 1. This is done atomically: even if multiple sessions execute nextval concurrently, each will safely receive a distinct sequence value. Advances the sequence object to its next value and returns that value.

The sequences