SQLite3; weird error

[TYR]

Has anyone else experienced a weird SQLite3 problem?

Going by the documentation at docs.python.org, the syntax is as
follows:
foo = sqlite3.connect(dbname) creates a connection object representing
the state of dbname and assigns it to variable foo. If dbname doesn't
exist, a file of that name is created.

To do anything with it, you then need to create a cursor object by
calling foo's method cursor (bar = foo.cursor).

You can now pass an SQL query or command to the DB by calling the
cursor object's method execute() with the SQL query as a quoted
statement.

(bar.execute("SELECT FROM squid WHERE squamous=True")

And then do other stuff.

Fine. When I call the cursor object, though, I get an AttributeError;
('builtinfunction_or_method object has no attribute 'execute')

Am running Python 2.5.1 on Mandriva Linux '08.

 

[Diez B. Roggisch]

Has anyone else experienced a weird SQLite3 problem?

Going by the documentation at docs.python.org, the syntax is as
follows:
foo = sqlite3.connect(dbname) creates a connection object representing
the state of dbname and assigns it to variable foo. If dbname doesn't
exist, a file of that name is created.

To do anything with it, you then need to create a cursor object by
calling foo's method cursor (bar = foo.cursor).

is that really from the docs? If yes, they are buggy.

The problem is pretty obvious: foo.cursor is NOT calling a method cursor on
foo. It's a reference to that very method.

So instead write

bar = foo.cursor()

and your done.

You can now pass an SQL query or command to the DB by calling the
cursor object's method execute() with the SQL query as a quoted
statement.

(bar.execute("SELECT FROM squid WHERE squamous=True")

And then do other stuff.

Fine. When I call the cursor object, though, I get an AttributeError;
('builtinfunction_or_method object has no attribute 'execute')

Which is a pretty acute description of the error: you are trying to get an
attribute (execute, which you ultimately expect to be a method) from a
method.

Diez

 

[Duncan Booth]

To do anything with it, you then need to create a cursor object by
calling foo's method cursor (bar = foo.cursor).

Perhaps this would work better if you actually try calling foo's method?

bar = foo.cursor()

Without the parentheses all you are doing is assigning the method to a
variable, not calling it.

 

[TYR]

Perhaps this would work better if you actually try calling foo's method?

bar = foo.cursor()

Without the parentheses all you are doing is assigning the method to a
variable, not calling it.

Ah. Apologies for a silly question.

 

[Bruno Desthuilliers]

TYR a écrit :

Has anyone else experienced a weird SQLite3 problem?

Going by the documentation at docs.python.org, the syntax is as
follows:
foo = sqlite3.connect(dbname) creates a connection object representing
the state of dbname and assigns it to variable foo. If dbname doesn't
exist, a file of that name is created.

To do anything with it, you then need to create a cursor object by
calling foo's method cursor (bar = foo.cursor).

You actually want :

bar = foo.cursor()

In Python, the parens are not optional when it comes to calling
functions - in fact, parens *are* the call operator. Without them, you
don't call the function (or method), but retrieve a reference to it.

You can now pass an SQL query or command to the DB by calling the
cursor object's method execute() with the SQL query as a quoted
statement.

(bar.execute("SELECT FROM squid WHERE squamous=True")

And then do other stuff.

Fine. When I call the cursor object, though, I get an AttributeError;
('builtinfunction_or_method object has no attribute 'execute')

Indeed. cf above.

 

[Bruno Desthuilliers]

TYR a écrit :

Ah. Apologies for a silly question.

Not so silly (considering you're somewhat new to Python, which seems
obvious here) - some languages work otherwise.