regex - PHP - Replace exact match preg_replace -

I'm trying to implement an lot simple PDO bindValue () function. (For educational purposes only)

So, in the first "frontend" code, I have a SQL query:

  Enter the log in value (: Referer ,: Id_cookie ,: id_cookie_com);  

And my code that looks like this:

  $ stmt-> gt; BindValue (': referer', 'test'); $ Stmt- & gt; Bind value (': id_cookie', 'test2'); $ Stmt- & gt; Byte value (': id_cookie_com', 'test3');  

I'm dividing my query, and I'm getting all the parameters that start with ":" in an array that works well.

  array ([0] = & gt ;: Referrer [1] =>: id_cookie [2] = & gt ;: id_cookie_com)  

But, when I try to change the parameter query, I have to face a small problem.

If I do this:

  Public function bundle ($ parameter, $ variable, $ type = zero) {$ this -> Sql = preg_replace ('/' parameter. '/', $ Variable, $ this- & gt; sql); }  

I'm receiving it as a result:

  Enter the log values ​​(test, test2, test3_com)  < / Pre> 
 I can not manage to remove  _com  at the end of the query I know why it is here, this is because my preg_replace matches my array with id_cookie , And I started with id_cookie with the variable. 
 
 How can I change the whole word to preg_replace ()? Use the word limit: 
 
  $ this-> Sql = preg_replace ("/ $ parameter \ b /", $ variable, $ this-> sql); // here __ ^^