It is also possible to use this the other way around: def foo(a, b, c):Īnother usage of the *l idiom is to unpack argument lists when calling a function. def bar(**kwargs):īoth idioms can be mixed with normal arguments to allow a set of fixed and some variable arguments: def foo(kind, *args, **kwargs): Keyword arguments except for those corresponding to a formal parameter as a dictionary. The *args will give you all function parameters as a tuple: def foo(*args): The *args and **kwargs is a common idiom to allow arbitrary number of arguments to functions as described in the section more on defining functions in the Python documentation. Otherwise, SQLite has no way of telling the difference between a NULL meaning "give me the next auto-increment value" and a NULL meaning "put a NULL value in serial_num because the column allows NULLs". To get the auto-increment value for serial_num. If you leave out the not null, you need to do your inserts like this: insert into dummy (name) values (?) The documentation on INTEGER PRIMARY KEY is a little unclear about what precisely is required for a column to be this special INTEGER PRIMARY KEY that auto-increments but the reality is that the column needs to be NOT NULL if you want to use the NULL value to mean "give me the next auto-incrementing value" when inserting: create table dummy ( We could change SQLite to conform to the standard (and we might do so in the future), but by the time the oversight was discovered, SQLite was in such wide use that we feared breaking legacy code if we fixed the problem. Unless the column is an INTEGER PRIMARY KEY SQLite allows NULL values in a PRIMARY KEY column. Unfortunately, due to a long-standing coding oversight, this is not the case in SQLite. ![]() ![]() From the fine manual:Īccording to the SQL standard, PRIMARY KEY should always imply NOT NULL.
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