A little confused as to what add image size actually does

Your not specifying a $crop value so your images are being cropped using a soft proportional crop. Set crop to TRUE for a hard crop.

add_image_size( 'sidebar_thumb', 46, 60, TRUE);

*no need to call function_exists for add_theme_support or add_image_size unless you want to be backwards compatible to pre 2.9.

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)