mysql - Vague SQL error... what's going on here? -

i'm getting error mysql useless error message i've ever seen:

error 1064 (42000): have error in sql syntax; check manual corresponds mysql server version right syntax use near 'not null, primary key (userid, tweetid), foreign key (userid) references user(' @ line 4 

great, check manual... >__>

here's sql source; i'm sure exceedingly simple familiar sql, i'm newb. me looks fine.

i'd have more well-formed question "what's error," error message vague, , me having little experience, i'm pretty lost.

create table user (     username        varchar(20)     not null,     userid          integer         not null,     fullname        varchar(100),     passwordhash    varchar(256)    not null,     email           varchar(256)    not null,     imageurl        varchar(200),     facebookurl     varchar(200),     tagline         varchar(140),     membersince     timestamp       not null,     primary key (userid) );  create table tweet (     tweetid integer                 not null,     userid integer                  not null,     content varchar(140)            not null,     timestamp                       not null,     primary key (tweetid),     foreign key (userid) references user(userid) );  create table hashtag (     tweetid integer                 not null,     content varchar(140)            not null,     primary key (content),     foreign key (tweetid) references tweet(tweetid) );  create table follows (     follower integer                not null,     followee integer                not null,     primary key (follower, followee),     foreign key (follower) references user(userid),     foreign key (followee) references user(userid) );  create table retweets (     tweetid integer                 not null,     userid integer                  not null,     timestamp                       not null,     primary key (userid, tweetid),     foreign key (userid) references user(userid),     foreign key (tweetid) references tweet(tweetid) );  create table mentions (     tweetid integer                 not null,     userid integer                  not null,     primary key (tweetid, userid),     foreign key (tweetid) references tweet(tweetid),     foreign key (userid) references user(userid) );  create table favorites (     tweetid integer                 not null,     userid integer                  not null,     primary key (tweetid, userid),     foreign key (tweetid) references tweet(tweetid),     foreign key (userid) references user(userid) );  create table cansee (     tweetid integer                 not null,     userid integer                  not null,     primary key (tweetid, userid),     foreign key (tweetid) references tweet(tweetid),     foreign key (userid) references user(userid) );  create table message (     messageid integer               not null,     senderid integer                not null,     receiverid integer              not null,     content varchar(140)            not null,     timestamp                       not null,     primary key (messageid),     foreign key (senderid) references user(userid),     foreign key (receiverid) references user(userid) ); 

when says "near __" it's saying right before point triggered error.

in case, that's word timestamp. listed timestamp type column, never gave name. perhaps should modified_on timestamp (or effect).