On Tue, Jun 12, 2012 at 7:04 AM, Paul Medynski <pmedyn...@rim.com> wrote:
> Hi Kevin, > > I understand the 'NOT NULL' column constraint and the syntax diagram and > text describe it quite well. What isn't described is whether or not > specifying simply 'NULL' is truly supported. For example, the following > create table statement is accepted by SQLite and appears to behave as > expected (column 'Id' is not null and column 'Name' is nullable): > > create table > ( > Id integer not null, > Name text null > ); > > I would like to know if 'NULL' is meant to be a valid column constraint or > not. It seems to work, but the documentation doesn't mention it explicitly. > The NULL constraint is parsed and then ignored. http://www.sqlite.org/src/artifact/f29df90bd3a?ln=299 > > Thanks, > -Paul > > > > > On 11-Jun-2012 15:35, Kevin Benson wrote: > >> On Mon, Jun 11, 2012 at 10:35 AM, Paul Medynski<pmedyn...@rim.com> >> wrote: >> >> Hi folks, >>> >>> I notice that the syntax diagram for 'create table' shows the >>> 'column-constraint' definition as requiring 'null' to always be preceded >>> by >>> 'not'. I don't see any definition that supports just 'null'. However, >>> when using SQLite3 3.7.3 or 3.7.9, I can create a table and specify any >>> column as "Foo<type> null", and it works as expected allowing the column >>> to contain null values. >>> >>> Is the syntax diagram simply out of date, or am I doing something that >>> appears to work, but will bite me in the end? :) >>> >>> >>> http://www.sqlite.org/draft/**lang_createtable.html<http://www.sqlite.org/draft/lang_createtable.html> >> >> "A CREATE TABLE command specifies the following attributes of the new >> table: >> - >> - >> - >> - >> - A default value or expression for each column in the table. >> - >> - >> - A set of SQL constraints for each table. SQLite supports UNIQUE, NOT >> NULL, CHECK and FOREIGN KEY constraints." >> >> "A table created using CREATE TABLE AS has no PRIMARY KEY and no >> constraints of any kind. The default value of each column is NULL." >> >> -- >> -- >> -- >> --Ô¿Ô-- >> K e V i N >> ______________________________**_________________ >> sqlite-users mailing list >> sqlite-users@sqlite.org >> http://sqlite.org:8080/cgi-**bin/mailman/listinfo/sqlite-**users<http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users> >> > > -- > > ------------------------------**-------------------------- > Paul Medynski BlackBerry Messenger Group > Senior Software Developer Research In Motion > pmedyn...@rim.com 50 Innovation Drive > Phone: +1 902 982 6134 Bedford, NS > Fax: +1 902 482 4380 B4B 0G4 > > > ______________________________**_________________ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-**bin/mailman/listinfo/sqlite-**users<http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users> > -- D. Richard Hipp d...@sqlite.org _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
