diff options
Diffstat (limited to 'models/nutrient.rkt')
| -rw-r--r-- | models/nutrient.rkt | 109 |
1 files changed, 41 insertions, 68 deletions
diff --git a/models/nutrient.rkt b/models/nutrient.rkt index 944583e..49921d7 100644 --- a/models/nutrient.rkt +++ b/models/nutrient.rkt @@ -1,26 +1,27 @@ #lang racket -(provide - ;; Model struct - nutrient - nutrient? - nutrient-id nutrient-name nutrient-formula - ;; Contracts - nutrient-value-pair/c - (contract-out - ;; SQL CRUD - [create-nutrient! (-> string? string? nutrient?)] - [get-nutrients (-> (listof nutrient?))] - [get-nutrient (->* () - (#:id (or/c #f exact-nonnegative-integer?) - #:name (or/c #f string?) - #:formula (or/c #f string?)) - (or/c nutrient? #f))] - [update-nutrient! (->* (nutrient?) - (#:name (or/c #f string?) - #:formula (or/c #f string?)) - (or/c nutrient? #f))] - [delete-nutrient! (-> nutrient? void?)])) +;; Model struct +(provide nutrient + nutrient? + nutrient-id + nutrient-name + nutrient-formula + ;; Contracts + nutrient-value-pair/c + ;; SQL CRUD + (contract-out [create-nutrient! (-> string? string? nutrient?)] + [get-nutrients (-> (listof nutrient?))] + [get-nutrient + (->* () + (#:id (or/c #f exact-nonnegative-integer?) + #:name (or/c #f string?) + #:formula (or/c #f string?)) + (or/c nutrient? #f))] + [update-nutrient! + (->* (nutrient?) + (#:name (or/c #f string?) #:formula (or/c #f string?)) + (or/c nutrient? #f))] + [delete-nutrient! (-> nutrient? void?)])) (require racket/contract db @@ -30,14 +31,9 @@ (struct nutrient (id name formula) #:transparent #:property prop:custom-write - (λ (v out _) - (fprintf out "#<~a ~a>" - (nutrient-id v) - (nutrient-name v)))) - -(define nutrient-value-pair/c - (cons/c nutrient? (and/c real? (>=/c 0)))) + (λ (v out _) (fprintf out "#<~a ~a>" (nutrient-id v) (nutrient-name v)))) +(define nutrient-value-pair/c (cons/c nutrient? (and/c real? (>=/c 0)))) ;; CREATE @@ -45,24 +41,18 @@ (or (get-nutrient #:name name #:formula formula) (begin (query-exec (current-conn) - (insert #:into nutrients - #:set [canonical_name ,name] [formula ,formula])) + (insert #:into nutrients #:set [canonical_name ,name] [formula ,formula])) (get-nutrient #:name name)))) - ;; READ (define (get-nutrients) (for/list ([(id* name* formula*) (in-query (current-conn) - (select id canonical_name formula - #:from nutrients - #:order-by id #:asc))]) + (select id canonical_name formula #:from nutrients #:order-by id #:asc))]) (nutrient id* name* formula*))) -(define (get-nutrient #:id [id #f] - #:name [name #f] - #:formula [formula #f]) +(define (get-nutrient #:id [id #f] #:name [name #f] #:formula [formula #f]) (define (where-expr) (define clauses (filter values @@ -73,47 +63,30 @@ [(null? clauses) ""] [else (format "WHERE ~a" (string-join clauses " AND "))])) (match (query-maybe-row (current-conn) - (string-join - `("SELECT id, canonical_name, formula" - "FROM nutrients" - ,(where-expr) - "ORDER BY id ASC" - "LIMIT 1"))) - [(vector id* name* formula*) - (nutrient id* name* formula*)] + (string-join `("SELECT id, canonical_name, formula" "FROM nutrients" + ,(where-expr) + "ORDER BY id ASC" + "LIMIT 1"))) + [(vector id* name* formula*) (nutrient id* name* formula*)] [#f #f])) - ;; UPDATE -(define (update-nutrient! nutrient - #:name [name #f] - #:formula [formula #f]) - (define id(nutrient-id nutrient)) +(define (update-nutrient! nutrient #:name [name #f] #:formula [formula #f]) + (define id (nutrient-id nutrient)) (cond [(and name formula) - (query-exec (current-conn) - (update nutrients - #:set [canonical_name ,name] [formula ,formula] - #:where (= id ,id)))] + (query-exec + (current-conn) + (update nutrients #:set [canonical_name ,name] [formula ,formula] #:where (= id ,id)))] [name - (query-exec (current-conn) - (update nutrients - #:set [canonical_name ,name] - #:where (= id ,id)))] + (query-exec (current-conn) (update nutrients #:set [canonical_name ,name] #:where (= id ,id)))] [formula - (query-exec (current-conn) - (update nutrients - #:set [formula ,formula] - #:where (= id ,id)))] + (query-exec (current-conn) (update nutrients #:set [formula ,formula] #:where (= id ,id)))] [else (void)]) - (or (get-nutrient #:id id) - (error 'update-nutrient! "No nutrient with id ~a" id))) - + (or (get-nutrient #:id id) (error 'update-nutrient! "No nutrient with id ~a" id))) ;; DELETE (define (delete-nutrient! nutrient) - (query-exec (current-conn) - (delete #:from nutrients - #:where (= id ,(nutrient-id nutrient))))) + (query-exec (current-conn) (delete #:from nutrients #:where (= id ,(nutrient-id nutrient))))) |