Математика учебници

Couldn't execute query.
select items.id, title, autor, image, cover, price, state, paused, customer_id, 0 as ntx from items inner join customers c on c.id = items.customer_id where (paused = 0 or paused is null) and CONCAT(",", `categories`, ",") REGEXP ',18,' and customer_id=796 and c.enabled = 1 union select * from (select items.id, title, autor, image, cover, price, state, paused, customer_id, 1 as ntx from items inner join customers c on c.id = items.customer_id where (paused = 0 or paused is null) and CONCAT(",", `categories`, ",") REGEXP ',18,' and `state`=4 and c.enabled = 1 union select items.id, title, autor, image, cover, price, state, paused, customer_id, 1 as ntx from items inner join customers c on c.id = items.customer_id where (paused = 0 or paused is null) and CONCAT(",", `categories`, ",") REGEXP ',18,' and `state`=0 and c.enabled = 1 union select items.id, title, autor, image, cover, price, state, paused, customer_id, 1 as ntx from items inner join customers c on c.id = items.customer_id where (paused = 0 or paused is null) and CONCAT(",", `categories`, ",") REGEXP ',18,' and `state`=3 and c.enabled = 1 union select items.id, title, autor, image, cover, price, state, paused, customer_id, 1 as ntx from items inner join customers c on c.id = items.customer_id where (paused = 0 or paused is null) and CONCAT(",", `categories`, ",") REGEXP ',18,' and (`state` <> 3 and `state` <> 4 and `state` <> 0) and c.enabled = 1) as T where customer_id <> 796 and `language`= 1
Unknown column 'language' in 'where clause'