Merge pull request #14 from Dr-Nekoma/constraints-proof-of-concept

Add local constraints as functions test

README.org

@@ -11,6 +11,12 @@ Do not use it professionally (it's always good to warn).
  - [X] Write the logical schema onto disk
  - [X] Reads of tables and schemas
  - [X] Persistent storage
+ - [ ] Constraints
+  + [ ] Add row-id to row reading from the disk
+  + [ ] Add local constraints to table struct
+  + [ ] Do a proof of concept using the backticked lambdas for local constraints
+  + [ ] Do a proof of concept using the hashed values for set constraints
+  + [ ] Add a serialization for constraints
  - [ ] Query Language
  - [ ] Server
  - [ ] Keys (logical and indexing)

ast.rkt

@@ -9,13 +9,14 @@
                     serializable?))
 (require threading)
 
+(provide check-local-constraints)
 (provide (struct+updaters-out table))
 (provide fields-size)
 (provide (struct+updaters-out procedure))
 (provide (struct+updaters-out fyeld))
+(provide (struct+updaters-out integer32))
 (provide (struct+updaters-out type))
 (provide stringl)
-(provide integer32)
 (require (only-in RacketowerDB/util define-serializable entity-structs))
 (require (submod RacketowerDB/util interfaces))
 (require (submod RacketowerDB/util hashable))
@@ -93,8 +94,12 @@
                (+ acc size)))
            0 fields-values)))
 
+(define (check-local-constraints table rows)
+  (let ((constraints (table-local-constraints table)))
+      (andmap (lambda (constraint) ((eval-syntax constraint) rows)) constraints)))
+
 (define-serializable table
-  (identifier row-id fields) #:transparent
+  (identifier row-id fields local-constraints) #:transparent
   #:methods gen:identifiable
   [(define (give-identifier self)
      (table-identifier self))]

main.rkt

@@ -13,44 +13,64 @@
   (require racket/base)
   (require racket/serialize)
   (require racket/class)
+  (require (rename-in RacketowerDB/ast (procedure? procedura?)))
   (require (submod RacketowerDB/io writer))
   (require (submod RacketowerDB/io reader))
   ;; (require (submod RacketowerDB/language parser))
   (require (submod RacketowerDB/backend server))
   (require RacketowerDB/util)
 
-  (require (except-in RacketowerDB/ast procedure?))
-  
+  (dynamic-require 'RacketowerDB/ast 0)
+
   (let* ((field-name (fyeld 0 (type 'VARCHAR 7)))
          (field-editor (fyeld 1 (type 'VARCHAR 5)))
          (field-year (fyeld 1 (type 'INTEGER 4)))
-         (programmer-table (table "table" 0 (make-hash `(("NAME" . ,field-name)
-                                                         ("EDITOR" . ,field-editor)))))
-         (car-table (table "table" 0 (make-hash `(("MODEL" . ,field-name)
-                                                  ("YEAR" . ,field-year)))))
+         (field-age (fyeld 2 (type 'INTEGER 4)))
+         (constraint-1 
+          #`(lambda (rows)
+             (andmap (lambda (row)
+                       (andmap (lambda (raw-field)
+				 (let ((raw-name (car raw-field))
+				       (raw-value (cdr raw-field)))
+				   (if (equal? raw-name "AGE")
+				       (>= (integer32-value raw-value) 50)
+				     #t))) row)) rows)))
+         (programmer-table (table 
+                              "table" 
+                              0 
+                              (make-hash `(("NAME" . ,field-name)
+                                           ("AGE" . ,field-age)
+                                           ("EDITOR" . ,field-editor)))
+                              (list constraint-1)))
+        ;  (car-table (table "table" 0 (make-hash `(("MODEL" . ,field-name)
+        ;                                           ("YEAR" . ,field-year)))))
          (procedure-test (procedure "procedure"))
          (schema (make-hash (list)))
          (row1 `(("NAME" . ,(stringl "Nathan"))
-                 ("EDITOR" . ,(stringl "Visual Studio Code"))))
+                 ("EDITOR" . ,(stringl "Visual Studio Code"))
+                 ("AGE" . ,(integer32 123))))
          (row2 `(("NAME" . ,(stringl "Lemos"))
-                 ("EDITOR" . ,(stringl "Emacs"))))
+                 ("EDITOR" . ,(stringl "Emacs"))
+                 ("AGE" . ,(integer32 100))))
          (row3 `(("MODEL" . ,(stringl "Ford"))
                  ("YEAR" . ,(integer32 1999))))
          (row4 `(("MODEL" . ,(stringl "Abc"))
                  ("YEAR" . ,(integer32 2013)))))
-    (hash-set! schema "CAR" car-table)
-    (hash-set! schema "TEST" procedure-test)
-    (hash-set! schema "PROGRAMMER" programmer-table)
-    (write-schema-to-disk schema)
-    (set! schema (read-schema-from-disk "schema"))
-    (println schema)
-    (set! schema (write-rows-to-disk schema "PROGRAMMER" (list row1 row2)))
-    (println (read-table-values-from-disk schema "PROGRAMMER"))
-    (write-table-to-disk programmer-table "PROGRAMMER")
-    (let ((read-table (read-table-from-disk "PROGRAMMER")))
-      (hash-set! schema "PROGRAMMER" read-table)
-      (set! schema (write-rows-to-disk schema "PROGRAMMER" (list row1 row2)))
-      (println schema))))
+    (check-local-constraints programmer-table (list row1 row2))
+;     (hash-set! schema "CAR" car-table)
+;     (hash-set! schema "TEST" procedure-test)
+;     (hash-set! schema "PROGRAMMER" programmer-table)
+;     (write-schema-to-disk schema)
+;     (set! schema (read-schema-from-disk "schema"))
+;     (println schema)
+;     (set! schema (write-rows-to-disk schema "PROGRAMMER" (list row1 row2)))
+;     (println (read-table-values-from-disk schema "PROGRAMMER"))
+;     (write-table-to-disk programmer-table "PROGRAMMER")
+;     (let ((read-table (read-table-from-disk "PROGRAMMER")))
+;       (hash-set! schema "PROGRAMMER" read-table)
+;       (set! schema (write-rows-to-disk schema "PROGRAMMER" (list row1 row2)))
+;       (println schema))
+      ))
 
   ;; (exit-handler)
   ;; (server-entrypoint)

samples/constraints.sql

@@ -0,0 +1,16 @@
+CREATE RELATION Person(
+    age INTEGER CHECK age >= 0 && age != 5,
+    name VARCHAR(64),
+    document_number DOCUMENT_NUMBER document_number = (name + (DATE_NOW() - age)),
+    KEY(document_number),
+    UNIQUE (age, name, document_number),
+    CHECK function_check_if_no_person_with_age_5()
+);
+
+KEY -> HASH document_number -> rowId
+UNIQUE -> HASH (age, name, document_number) -> rowId
+
+RowId = 1 (1,"Lemos","Lemos-2022")
+RowId = 2 (1,"Marinho","Marinho-2022")
+RowId = 3 (1,"Magueta","Magueta-2022")
+