There is a sample in a variable.

Tell me how to apply the if / else in SQL .
For example, if advert.hide = 'show' , then ….. otherwise another.

$ db_query = "select *
  from ".db_pref." Advert Advert "
  . "WHERE"
  . "Advert.hide = 'Show'"
  . "" and advert.end_putdate & gt; "$ globals [" TimeGlobal "]." "
  . "Order by Premium_adv Desc, Sort_time Desc Limit" .kol_new_advert_to_glav;

Answer 1, Authority 100%

Use the if function:

select if (advert.hide = 'show', 'Published', 'hidden') from ...

The function looks in general form, so:

if (expr1, expr2, expr3)

If Expr1 Truth then if () Returns Expr2 , otherwise returns Expr3 .

Answer 2, Authority 50%

To solve this task, it is best to use the case expression, it can be sent to the desired hide = 'show' and depending on whether it takes True or False You need to return the value. One of the possible uses of Case is given below

$ db_query = "select
  id
  Hide
  END_PUTDATE,
  Premium_adv,
  sort_time
  Case When Hide = 'Show' Then 'Published' ELSE 'Not Posted by' End As Hide
from ".db_pref." Advert Advert "
. "WHERE"
. "Advert.hide = 'Show'"
. "" and advert.end_putdate & gt; "$ globals [" TimeGlobal "]." "
. "Order by Premium_adv Desc, Sort_time Desc Limit" .kol_new_advert_to_glav;