PHP / MYSQL语法错误

Question

Could you help me figure out what could be wrong with this line?

$sql45="UPDATE invite_keys SET use=$num WHERE key=$getkey LIMIT 1 ";

I did some error checking and was able to determine that the above line has incorrect syntax, I just cannot figure out what exactly is causing it to fail. Does anyone know?

Output of error: MySQL Query failed with error: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'use=1 WHERE key=2598131858 LIMIT 1' at line 1

Thank you for your help!

Answer 1

USE and KEY are reserved words in MySQL and must be surrounded by backticks in your query:

"UPDATE invite_keys SET `use` = $num WHERE `key` = $getkey LIMIT 1"

See the list of reserved words in the documentation .

Answer 2

$sql45="UPDATE `invite_keys` SET `use`=" . $num . " WHERE `key`=" . $getkey . " LIMIT 1 ";

关键是-至少对字段始终使用``...

Answer 3

Mark's answer about the back ticks is right. Watch for using keywords in both SQL statements and PHP variables. It's easy - and sometimes tempting - to do.

A good thing to do when troubleshooting is to echo your SQL string so you can see it in full, that can give you a hint.

If that doesn't help, try pasting into phpmysqladmin or another mySQL interface and see what error that gives. Sometimes it is more explanatory than what you see on a web page.