PHP和Mysql || '或'语法？

In mysql I have something like:

$currentname = mysql_query("SELECT * FROM posts LIMIT $start, 5 WHERE ");   

How can i do something like this below that works:

$currentname = mysql_query("SELECT * FROM posts LIMIT $start, 5 WHERE `title` LIKE '%{Hello world}%' || Where `text` LIKE '%{Hello World}%'");

Something like above that will actually work.

Try this:

$queryResult = mysql_query("SELECT * FROM posts WHERE `title` LIKE '%{Hello world}%' OR `text` LIKE '%{Hello World}% LIMIT $start, 5'");
$currentName = mysql_fetch_assoc($queryResult);

if you expect many results...

   while($currentName = mysql_fetch_assoc($queryResult)) {
     //your code here...
   }

Replace || with OR and remove the extra WHERE that comes after it. In SQL, || is OR and && is AND. You can read more here.

Note: Please take time to read manuals, it absolutely helps.

You can use OR in MySql, and it is likely very suitable for most situations.

OR however has a slight disadvantage performance wise as for each OR query the whole query is ran again. I am no MySql performance guru, but it would seem UNION is better optimized. So in general, and at lest with more OR statements you should use a UNION like this:

SELECT your_union_result.* FROM
(
SELECT * FROM posts WHERE `title` LIKE '%{Hello world}%'
UNION
SELECT * FROM posts WHERE `text` LIKE '%{Hello World}%'
) AS your_union_result
ORDER BY your_union_result.order_column
LIMIT $start, 5

Please note: My version has a subquery. You need it in case you want to order the result or limit the total rows. You now have a few options to fetch the actual result.

You can fetch_assoc(), fetch_array() and so on row by row. It is unclear for me what you want as the actual result. The $currentname indicates a post or user name, but a limit of $start, 5, indicates you want a list.

Go ahead and read http://php.net/manual/en/function.mysql-fetch-array.php and the other fetch functions. If you need more help, please update your question to be a bit more specific.