If you’re getting an error that reads something like “MINVALUE (1) must be less than MAXVALUE (1)” in PostgreSQL when you’re trying to create a sequence, it’s probably because your sequence’s minimum possible value is higher than the maximum value.
To fix this issue, be sure that the sequence’s maximum value is greater than the minimum value.
If you’re getting an error that reads something like “START value (101) cannot be greater than MAXVALUE (100)” in PostgreSQL when you’re trying to create a sequence, it’s probably because your sequence’s maximum possible value is lower than the start value.
To fix this issue, change either the start value or maximum value so that the maximum value is greater than the start value.
If you’re getting an error in PostgreSQL that reads something like “cannot insert into column” with detail that explains that the “…is an identity column defined as GENERATED ALWAYS“, it’s probably because you’re trying to insert your own value into an identity column that was created with the GENERATED ALWAYS option, but you’re not explicitly overriding the column from auto generating its own value.
To fix this issue, use OVERRIDING SYSTEM VALUE when inserting the value.
If you’re getting an error that reads something like “nextval: reached maximum value of sequence “sequence1” (3)” in PostgreSQL, it’s probably because you’re trying to generate a new value from a sequence, but the sequence has already reached its maximum value.
We have quite a few options when it comes to dealing with this issue.
If you’re getting an error that reads something like “lastval is not yet defined in this session” when calling the lastval() function in PostgreSQL, it’s probably because nextval() hasn’t yet been called in the current session.
If you want to avoid this error, only call the lastval() function when you know that nextval() has been called at least once in the current session.
In PostgreSQL, we can use the generate_series() function to return a series of values between a given start and stop point. This can be a series of numbers or a series of timestamps.
The function returns a set containing the series.
If you’re getting an error that reads something like “START value (0) cannot be less than MINVALUE (1)” in PostgreSQL when you’re trying to create a sequence, it’s because your sequence’s start value is lower than its minimum value, when it should be at least the same or higher.
To fix this issue, be sure that the sequence’s start value is at least the same or greater than the minimum value.
In PostgreSQL, we can use the setval() function to set a sequence’s value.
We specify the value when we call the function. We also have the option of setting its is_called flag.
In PostgreSQL, the currval() function returns the value most recently returned by nextval() for the specified sequence in the current session.
The currval() function is very similar to the lastval() function, except that lastval() doesn’t require the name of a sequence like currval() does. That’s because lastval() doesn’t report on any particular sequence – it reports on the last time nextval() was used in the current session, regardless of which sequence was used. The currval() on the other hand, only reports on the specified sequence.