MySQL where clause equals anything (SELECT * WHERE col = ANY_VALUE)

Question

I\'d like to create a query in MySQL that has an optional value. When the value is specified the query is filtered by that value, when the value is not all rows are returned

Answer 1

As far as I know, no such "any" placeholder exists.

If you can use LIKE, you could do

SELECT * FROM table WHERE item LIKE '%'

if you can append a condition, you could nullify the item clause like this:

SELECT * FROM table WHERE item = ? OR 1=1

(won't work in your example though, because you are passing "item" as a parameter)

That's all the options I can see - it's probably easiest to work with two queries, removing the WHERE clause altogether in the second one.

This would probably work, but I*m not sure whether it's a good idea from a database point of view.

public function doQuery($item = 'ANY_VALUE') {
  $query = "SELECT * FROM table WHERE item = ? OR 1 = ?";
  db->fetchAll($query,array($item, ($item == 'ANY_VALUE' ? 1 : 0))
  ...
}