关于insert语句插入数据到mysql数据库的问题

[gullsky]

$sql="insert into friend_user(userid,name,sfz,race,nation,sex,zhz,birthday,np,pass,repass,sorts,mode,entrance,edu,gra,magra,schmode,specialty,uncode,graun,shcode,schname,massort,masspe,mcode,massch,mascode,masunit,doccode,docunit,docdate,dspecode,docdate,dspecode,docspe,isfirst,teaname,letterid,asssort,pname,pamount,ptheme,ptime,porigin,anstime,psort,apubin,appubout,apubcon,apubcont,sci,ei,istp,awf,awt,awth,awfo,bwf,bwt,bwth,patent,remark) values ('$userid','$name','$sfz','$race','$nation','$sex','$zhz','$birthday','$np','$pass','$repass','$sorts','$mode','$entrance','$edu','$gra','$magra','$schmode','$specialty','$uncode','$graun','$shcode','$schname','$massort','$masspe','$mcode','$massch','$mascode','$masunit','$doccode','$docunit','$docdate','$dspecode','$docdate','$dspecode','$docspe','$isfirst','$teaname','$letterid','$asssort','$pname','$pamount','$ptheme','$ptime','$porigin','$anstime','$psort','$apubin','$appubout','$apubcon','$apubcont','$sci','$ei','$istp','$awf','$awt','$awth','$awfo','$bwf','$bwt','$bwth','$patent','$remark')";
$result=mysql_query($sql,$db);
mysql_close($db);
echo "<script language=javascript>alert('用户注册完成，请牢记帐号和密码!');location.href='index.php'</script>";
是不是insert语句限制一次插入的变量个数？
为什么总是不能插入数据到数据库？