When to use ' ' vs ` ` ?

[TheBigK]

I'm not sure how to describe this. But here's a code from my datawriter that was throwing error "The field sf_id is not recognised'. I had to change the `sf_id` to 'sf_id'

'sf_id' => array('type' => self::TYPE_UINT, 'autoIncrement' => true),

I've seen that many times while writing SQL queries, I must use `something` over 'something'. Can someone point out the difference?

 

[Jake B.]

That isn't a query, you should use ` in queries around table/field names, not in array keys

 

[Chris D]

` (backtick) is pretty much used exclusively to escape column and table names in MySQL.
' (single quote) is used to enclose strings in PHP and MySQL. In most cases you can also use " (double quote)

 

[TheBigK]

Thanks @Jake B. and @Chris D . That just helped me save a lot of time.

 

[Mr. Goodie2Shoes]

PHP has a different use for backticks: PHP: Execution Operators - Manual