Question

I have two tables: searches and commonWords. Given user input Q, if Q is not found in commonWords, I want to insert it into searches.

To be honest I’m just completely confused how I would do this. How can I combine INSERT INTO with the whole SELECT .. WHERE thing?

I know I can do it with two queries:

$db->query('SELECT * FROM commonWords WHERE word = ?', $q);
if ($db->affectedRows() > 0)
  $db->query('INSERT INTO searches (search) VALUES (?)', $q);

However, I would like to confine this operation to one query.

Thanks for any help!

Answer 1

try this if you want to insert a row that exisists in commonWords

insert into searches (search) select word from commonWords where word = ?

but you have to be carefull because you have to set a unique index for searches.search
if not you could insert multiple rows of the same value

if you want insert a non existing word into searches, then you have to try this

$db->query('insert into searches (search) select case when count(word) = 0 then \'?\' else NULL end as word from commonWords where word = ?', $q);