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Hans Dijkema
2025-07-09 15:52:13 +02:00
parent 2a9ae580a0
commit 1717e0b01e
1 changed files with 12 additions and 9 deletions
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21
scribblings/roos.scrbl
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@@ -144,13 +144,14 @@ See the full SQLite example in the next section.
Below is an example SQLite backend implementation that stores fields in a table:
@#reader scribble/comment-reader
@racketblock[
(require db)
(require racket/vector)
@; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
@; ;; Conversion of field values
@; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Conversion of field values
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(define (value->string s-expr)
(let ((o (open-output-string)))
@@ -161,9 +162,9 @@ Below is an example SQLite backend implementation that stores fields in a table:
(let ((o (open-input-string str)))
(read o)))
@; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
@; ;; Database storage backend
@; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Database storage backend
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(define conn (sqlite3-connect #:database "roos.db" #:mode 'create))
(query-exec conn "CREATE TABLE IF NOT EXISTS store (class TEXT, id TEXT, field TEXT, val TEXT)")
@@ -214,14 +215,16 @@ Below is an example SQLite backend implementation that stores fields in a table:
This example builds an address book with persistent reference to persons, using ROOS' object ID mechanism.
@#reader scribble/comment-reader
@racketblock[
(require racket/vector)
;; person class
(def-roos (person) this (supers)
(persist (name ""))
(persist (tel "")))
;; book class
(def-roos (book) this (supers)
(persist (ids (list)))
(persist (name ""))
@@ -254,7 +257,7 @@ This example builds an address book with persistent reference to persons, using
)
@; ;; Create sample data
;; Create sample data
(define b (-! book))
(define (adder n t)
@@ -270,7 +273,7 @@ This example builds an address book with persistent reference to persons, using
(-> b (for-each (lambda (p) (displayln (-> p name)))))
@; ;; Reopen addressbook later from persistent storage
;; Reopen addressbook later from persistent storage
(define a (-! book))
(-> b (for-each (lambda (p) (displayln (-> p name)))))