reserved keywords in mysql

today,  I created 3 mysql tables for my facebook app, to save user "status" "comment" "like" infomation.

I did not think too much before i created the 3 tables with name: status, comment, like respectively.
then, I found I could insert content into status and comment table while always failed the like table .

/*php code*/

mysql_query("INSERT INTO like (object_id,user_id,type) VALUES ('$comment_id', '$like_user_id','comment')");//error

I did know the 'like' is one mysql reserved keyword, however, i did not think that way at that very moment

then when I changed the table name from 'like' to 'likes', then it works.

/*php code*/

mysql_query("INSERT INTO likes (object_id,user_id,type) VALUES ('$comment_id', '$like_user_id','comment')");//correct

//or
mysql_query("INSERT INTO my_like (object_id,user_id,type) VALUES ('$comment_id', '$like_user_id','comment')");//correct

Here is the official mysql reserved keyword.
http://dev.mysql.com/doc/refman/5.0/en/reserved-words.html

however, I think it's safe to name your table or column as: my_xxx.

issue on inserting text or varchar values on mysql

when we insert text or varchar values into tables on mysql, we usually use the following format

mysql_query("INSERT INTO user (userid, name, gender) VALUES ('$user_id', '$user_name', '$user_gender'");

instead of

mysql_query("INSERT INTO user (userid, name, gender) VALUES ($user_id, $user_name, $user_gender");

yes, the difference is '$user_name' and  $user_name.

the advantage of former is that:
if your name is zhiguang cao (yes, there is one blank space between given name and surname )

when you insert  $user_name, it will be considered as two items: zhiguang  and cao respectively, and thus the result would not be correct generally.

while if you insert '$user_name', it will be considered as one item: 'zhiguang cao' would be one item instead of two.

I took me hours to find this problem although it seems not a big deal. thanks chenbo's help!