The where criterion expects a single argument, which is the conditional part of a (MY)SQL query. SPIP uses this value by combining it with the other conditional elements from the other criteria in the loop.
Examples
The where criterion allows ORs to be performed:
<BOUCLE_or(ARTICLES){statut=redac}{where id_rubrique=10 OR id_rubrique=20}>
It allows you to call MYSQL functions:
<BOUCLE_or(ARTICLES){where YEAR(date_creation) > 1970}>
It allows you to make subqueries (here in the plug-in info_site) :
{where id_organisation IN (SELECT id_objet FROM spip_projets_liens WHERE objet='organisation' AND id_projet=#ID_PROJET)}
The where criterion makes it possible to use a condition where the 2 terms of the test are fields of the table: we want to find the articles with the same section id and sector id
<BOUCLE_where(ARTICLES){where id_rubrique = id_secteur}>
Note that it would have been possible to do it without where in all these cases:
- with {id_rubrique IN #LIST{10,20}}
- with {date_creation>1970-01-01}
- with a joint in the SPIP loop
- with a wrapping loop
Preparing the condition
When there is a comma in the where expression, often because of a MYSQL function call, include the condition in a #VAL tag.
Example :
{where #VAL{"DATE_ADD(date_debut,INTERVAL 2 WEEK)<date_fin"}}
When the conditions are even more complex, it is necessary to prepare the query in a #SET :
#SET{where, here complex calculation}
<BOUCLE_root_articles(ARTICLES) {...}{where #GET{where}}>
Conditional where criterion
The criterion also allows comparison with the value of where passed into the environment, if it exists: {where?}