SQL query

HI,

I want to select station_nom, kpi_cate, kpi_nom, kpi_valeur, kpi_date, kpi_heure into the table kpi between two dates. I show you my controller and my model that I wrote. Unfortunately, my request generates the error below:

Error Number: 1064

Erreur de syntaxe près de '`NULL` AND `kpi_date` > `IS` `NULL`' à la ligne 10

SELECT `station_nom`, `kpi_cate`, `kpi_nom`, `kpi_valeur`, `kpi_date`, `kpi_heure` FROM `kpi` JOIN `station_base` ON `station_base`.`station_id` = `kpi`.`station_id` WHERE `type_reseau` IS NULL AND `kpi_type` IS NULL AND `region` IS NULL AND `ville` IS NULL AND `centre` IS NULL AND `site` IS NULL AND `kpi_date` < `IS` `NULL` AND `kpi_date` > `IS` `NULL`

Filename: C:/wamp/www/CodeIgniter/system/database/DB_driver.php

Line Number: 691