Select statement when WHERE is variable

Anon

I need to create the following select statement:

select * from merchandise_sizes where $column_name !=0

I do not know the name of the column for the WHERE, it is a variable pulled from the database in an earlier select statement. I have echoed $column_name, and I have successfully set the variable, but the query statement will not accept a variable. If i hard code the where statement, of course it works.

But, how can I use WHERE if the column name is a variable?

Thanks

Anon

Have a look at variable variables (yep, tounge twister)

http://uk.php.net/manual/en/language.variables.variable.php (UK mirror)

Should help.

Justin

tomhath

Assuming you are in php, there's nothing special about it. When you build the query string the value of the variable gets substituted and mysql only sees the final query string:

<?php

$column_name = "Col_1";
$query = "select from merchandise_sizes where " . $column_name . " !=0";
echo $query;
echo "<br>";
$column_name = "Col_2";
$query = "select from merchandise_sizes where " . $column_name . " !=0";
echo $query;
?>