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#lang racket
(provide
;; Struct definitions
crop
crop?
crop-id crop-name
;; SQL CRUD
(contract-out
[create-crop! (-> string? void?)]
[get-crops (-> (listof crop?))]
[get-crop (->* ()
(#:id (or/c #f exact-nonnegative-integer?)
#:name (or/c #f string?))
(or/c crop? #f))]
[update-crop! (->* (exact-nonnegative-integer?)
(#:name (or/c #f string?))
(or/c crop? #f))]
[delete-crop! (-> exact-nonnegative-integer? void?)]))
(require racket/contract
db
sql
"../db/conn.rkt")
(struct crop (id name) #:transparent)
;; CREATE
(define (create-crop! name)
(define existing-crop (get-crop #:name name))
(define (new-crop)
(query-exec (current-conn)
(insert #:into crops
#:set [canonical_name ,name])))
(or existing-crop
(new-crop)))
;; READ
(define (get-crops)
(for/list ([(id* name*)
(in-query (current-conn)
(select id canonical_name
#:from crops
#:order-by id #:asc))])
(crop id* name*)))
(define (get-crop #:id [id #f]
#:name [name #f])
(define (where-expr)
(define clauses
(filter values
(list (and id (format "id = ~e" id))
(and name (format "canonical_name = ~e" name)))))
(cond
[(null? clauses) ""]
[else (format "WHERE ~a" (string-join clauses " AND "))]))
(define query (string-join
`("SELECT id, canonical_name"
"FROM crops"
,(where-expr)
"ORDER BY id ASC"
"LIMIT 1")))
(match (query-maybe-row (current-conn) query)
[(vector id* name*)
(crop id* name*)]
[#f #f]))
;; UPDATE
(define (update-crop! id
#:name [name #f])
(cond
[name
(query-exec (current-conn)
(update crops
#:set [canonical_name ,name]
#:where (= id ,id)))]
[else (void)])
(or (get-crop #:id id)
(error 'update-crop! "No crop with id ~a" id)))
;; DELETE
(define (delete-crop! id)
(query-exec (current-conn)
(delete #:from crops #:where (= id ,id))))
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