If you want to comment out all those lines use
/CREATE TABLE onlinesurvey (
id NOT NULL auto_increment,
gender int(11) NOT NULL default '0',
age int(11) NOT NULL default '0',
suptype int(11) NOT NULL default '0',
knowledge int(11) NOT NULL default '0',
overall int(11) NOT NULL default '0',
speed int(11) NOT NULL default '0',
repknowledge int(11) NOT NULL default '0',
results int(11) NOT NULL default '0',
personability int(11) NOT NULL default '0',
recommend int(11) NOT NULL default '0',
PRIMARY KEY (id)
);/
// will only comment out a single line of code until it reaches an invisible newline character created when you hit enter or return in the editor.
//CREATE TABLE onlinesurvey (id NOT NULL auto_increment,gender int(11) NOT NULL default '0',age int(11) NOT NULL default '0',suptype int(11) NOT NULL default '0',knowledge int(11) NOT NULL default '0',overall int(11) NOT NULL default '0',speed int(11) NOT NULL default '0',repknowledge int(11) NOT NULL default '0',results int(11) NOT NULL default '0',personability int(11) NOT NULL default '0',recommend int(11) NOT NULL default '0',PRIMARY KEY (id));
would work because although it's over multiple lines, there is no newline character
It's best to use an editor that had syntax highlighting so you can pick these mistakes up.