如何在SQL中存储PHP变量，以便在检索时它仍然是变量（不是值）

Question

I want to save a string in SQL such that each time it is called, part of the string is a variable. For example, if the string is "Hello my name is $name", I want to save it such that whenever it is retrieved, $name is still a variable:

$name = "Doug";
$row = mysql_fetch_array($mysql_query_result);

$message = $row['message'];  // "Hello, my name is $name."

echo $message;  // "Hello, my name is Doug."

One way would be:

str_replace('$name', $name, $message);  // called before echo

I've never been too comfortable with variable variables, but from what I understand, a general function for the str_replace method could be made using them.

My question is whether or not this is necessary? Is there a much easier way to store a variable in SQL and keep it variable?

Answer 1

You could make it a format string for sprintf .

$name = "Doug";
$row = mysql_fetch_array($mysql_query_result);

$message = sprintf($row['message'], $name);  // "Hello, my name is %s."

echo $message;  // "Hello, my name is Doug."

Or str_replace as you said.

Answer 2

You could use eval() but I strongly suggest to not use it. Instead use a placeholder in your string and replace it when outputing, eg using sprintf() or str_replace() as you suggest.

Answer 3

You could also do it at the query level using replace() :

//part of the query
$query .= "SELECT replace('message','\$name','{$name}')";