开发者

How does {} affect a MySQL Query in PHP? [duplicate]

开发者 https://www.devze.com 2023-02-19 01:23 出处:网络
This question already has answers here: Curly braces in string in PHP (4 answers) Closed 1 year ago. 开发者_如何学JAVA
This question already has answers here: Curly braces in string in PHP (4 answers) Closed 1 year ago. 开发者_如何学JAVA

What is the difference between the following 2 queries?

mysql_query("UPDATE table SET name = '$name'");

mysql_query("UPDATE table SET name = '{$name}'");


ON the SQL side, there is absolutely no difference : the two queries are exactly the same.
(you can check that by echo-ing them)

{$variable} is a more complete syntax of $variable, that allows one to use :

  • "this is some {$variable}s"
  • "{$object->data}"
  • "{$array['data']}"
  • "{$array['data']->obj->plop['test']}"


For more informations, you should read the Variable parsing / Complex (curly) syntax section of the manual (quoting a few bits) :

This isn't called complex because the syntax is complex, but because it allows for the use of complex expressions.

Any scalar variable, array element or object property with a string representation can be included via this syntax.
Simply write the expression the same way as it would appear outside the string, and then wrap it in { and }.


The curly braces "escape" the PHP variable and are not passed to MySQL. With a simple variable like $name it doesn't make a difference but with something like $user['name'] it does. So there is nothing different between the two queries you have posted in your question.


This query can be used if you want to pass a single variable:

mysql_query("UPDATE table SET name = '$name'");

This can be used if you are passing a value from an array's particular index.

mysql_query("UPDATE table SET name = '{$1}'",$name);

By the way your both queries were also correct in their means.

0

精彩评论

暂无评论...
验证码 换一张
取 消