sql/oodml.lisp

   1 ;;;; -*- Mode: LISP; Syntax: ANSI-Common-Lisp; Base: 10 -*-
   2 ;;;; *************************************************************************
   3 ;;;;
   4 ;;;; $Id$
   5 ;;;;
   6 ;;;; The CLSQL Object Oriented Data Manipulation Language (OODML).
   7 ;;;;
   8 ;;;; This file is part of CLSQL.
   9 ;;;;
  10 ;;;; CLSQL users are granted the rights to distribute and use this software
  11 ;;;; as governed by the terms of the Lisp Lesser GNU Public License
  12 ;;;; (http://opensource.franz.com/preamble.html), also known as the LLGPL.
  13 ;;;; *************************************************************************
  14
  15 (in-package #:clsql-sys)
  16
  17
  18 (defun key-qualifier-for-instance (obj &key (database *default-database*))
  19   (let ((tb (view-table (class-of obj))))
  20     (flet ((qfk (k)
  21              (sql-operation '==
  22                             (sql-expression :attribute
  23                                             (view-class-slot-column k)
  24                                             :table tb)
  25                             (db-value-from-slot
  26                              k
  27                              (slot-value obj (slot-definition-name k))
  28                              database))))
  29       (let* ((keys (keyslots-for-class (class-of obj)))
  30              (keyxprs (mapcar #'qfk (reverse keys))))
  31         (cond
  32           ((= (length keyxprs) 0) nil)
  33           ((= (length keyxprs) 1) (car keyxprs))
  34           ((> (length keyxprs) 1) (apply #'sql-operation 'and keyxprs)))))))
  35
  36 ;;
  37 ;; Function used by 'generate-selection-list'
  38 ;;
  39
  40 (defun generate-attribute-reference (vclass slotdef)
  41   (cond
  42    ((eq (view-class-slot-db-kind slotdef) :base)
  43     (sql-expression :attribute (view-class-slot-column slotdef)
  44                     :table (view-table vclass)))
  45    ((eq (view-class-slot-db-kind slotdef) :key)
  46     (sql-expression :attribute (view-class-slot-column slotdef)
  47                     :table (view-table vclass)))
  48    (t nil)))
  49
  50 ;;
  51 ;; Function used by 'find-all'
  52 ;;
  53
  54 (defun generate-selection-list (vclass)
  55   (let ((sels nil))
  56     (dolist (slotdef (ordered-class-slots vclass))
  57       (let ((res (generate-attribute-reference vclass slotdef)))
  58         (when res
  59           (push (cons slotdef res) sels))))
  60     (if sels
  61         sels
  62         (error "No slots of type :base in view-class ~A" (class-name vclass)))))
  63
  64
  65
  66 (defun generate-retrieval-joins-list (vclass retrieval-method)
  67   "Returns list of immediate join slots for a class."
  68   (let ((join-slotdefs nil))
  69     (dolist (slotdef (ordered-class-slots vclass) join-slotdefs)
  70       (when (and (eq :join (view-class-slot-db-kind slotdef))
  71                  (eq retrieval-method (gethash :retrieval (view-class-slot-db-info slotdef))))
  72         (push slotdef join-slotdefs)))))
  73
  74 (defun generate-immediate-joins-selection-list (vclass)
  75   "Returns list of immediate join slots for a class."
  76   (let (sels)
  77     (dolist (joined-slot (generate-retrieval-joins-list vclass :immediate) sels)
  78       (let* ((join-class-name (gethash :join-class (view-class-slot-db-info joined-slot)))
  79              (join-class (when join-class-name (find-class join-class-name))))
  80         (dolist (slotdef (ordered-class-slots join-class))
  81           (let ((res (generate-attribute-reference join-class slotdef)))
  82             (when res
  83               (push (cons slotdef res) sels))))))
  84     sels))
  85
  86
  87 ;; Called by 'get-slot-values-from-view'
  88 ;;
  89
  90 (defmethod update-slot-from-db ((instance standard-db-object) slotdef value)
  91   (declare (optimize (speed 3) #+cmu (extensions:inhibit-warnings 3)))
  92   (let* ((slot-reader (view-class-slot-db-reader slotdef))
  93          (slot-name   (slot-definition-name slotdef))
  94          (slot-type   (specified-type slotdef)))
  95     (cond ((and value (null slot-reader))
  96            (setf (slot-value instance slot-name)
  97                  (read-sql-value value (delistify slot-type)
  98                                  (view-database instance)
  99                                  (database-underlying-type
 100                                   (view-database instance)))))
 101           ((null value)
 102            (update-slot-with-null instance slot-name slotdef))
 103           ((typep slot-reader 'string)
 104            (setf (slot-value instance slot-name)
 105                  (format nil slot-reader value)))
 106           ((typep slot-reader '(or symbol function))
 107            (setf (slot-value instance slot-name)
 108                  (apply slot-reader (list value))))
 109           (t
 110            (error "Slot reader is of an unusual type.")))))
 111
 112 (defmethod key-value-from-db (slotdef value database)
 113   (declare (optimize (speed 3) #+cmu (extensions:inhibit-warnings 3)))
 114   (let ((slot-reader (view-class-slot-db-reader slotdef))
 115         (slot-type (specified-type slotdef)))
 116     (cond ((and value (null slot-reader))
 117            (read-sql-value value (delistify slot-type) database
 118                            (database-underlying-type database)))
 119           ((null value)
 120            nil)
 121           ((typep slot-reader 'string)
 122            (format nil slot-reader value))
 123           ((typep slot-reader '(or symbol function))
 124            (apply slot-reader (list value)))
 125           (t
 126            (error "Slot reader is of an unusual type.")))))
 127
 128 (defun db-value-from-slot (slotdef val database)
 129   (let ((dbwriter (view-class-slot-db-writer slotdef))
 130         (dbtype (specified-type slotdef)))
 131     (typecase dbwriter
 132       (string (format nil dbwriter val))
 133       ((and (or symbol function) (not null)) (apply dbwriter (list val)))
 134       (t
 135        (database-output-sql-as-type
 136         (typecase dbtype
 137           (cons (car dbtype))
 138           (t dbtype))
 139         val database (database-underlying-type database))))))
 140
 141 (defun check-slot-type (slotdef val)
 142   (let* ((slot-type (specified-type slotdef))
 143          (basetype (if (listp slot-type) (car slot-type) slot-type)))
 144     (when (and slot-type val)
 145       (unless (typep val basetype)
 146         (error 'sql-user-error
 147                :message
 148                (format nil "Invalid value ~A in slot ~A, not of type ~A."
 149                        val (slot-definition-name slotdef) slot-type))))))
 150
 151 ;;
 152 ;; Called by find-all
 153 ;;
 154
 155 (defmethod get-slot-values-from-view (obj slotdeflist values)
 156     (flet ((update-slot (slot-def values)
 157              (update-slot-from-db obj slot-def values)))
 158       (mapc #'update-slot slotdeflist values)
 159       obj))
 160
 161 (defmethod update-record-from-slot ((obj standard-db-object) slot &key
 162                                     (database *default-database*))
 163   (let* ((database (or (view-database obj) database))
 164          (vct (view-table (class-of obj)))
 165          (sd (slotdef-for-slot-with-class slot (class-of obj))))
 166     (check-slot-type sd (slot-value obj slot))
 167     (let* ((att (view-class-slot-column sd))
 168            (val (db-value-from-slot sd (slot-value obj slot) database)))
 169       (cond ((and vct sd (view-database obj))
 170              (update-records (sql-expression :table vct)
 171                              :attributes (list (sql-expression :attribute att))
 172                              :values (list val)
 173                              :where (key-qualifier-for-instance
 174                                      obj :database database)
 175                              :database database))
 176             ((and vct sd (not (view-database obj)))
 177              (insert-records :into (sql-expression :table vct)
 178                              :attributes (list (sql-expression :attribute att))
 179                              :values (list val)
 180                              :database database)
 181              (setf (slot-value obj 'view-database) database))
 182             (t
 183              (error "Unable to update record.")))))
 184   (values))
 185
 186 (defmethod update-record-from-slots ((obj standard-db-object) slots &key
 187                                      (database *default-database*))
 188   (let* ((database (or (view-database obj) database))
 189          (vct (view-table (class-of obj)))
 190          (sds (slotdefs-for-slots-with-class slots (class-of obj)))
 191          (avps (mapcar #'(lambda (s)
 192                            (let ((val (slot-value
 193                                        obj (slot-definition-name s))))
 194                              (check-slot-type s val)
 195                              (list (sql-expression
 196                                     :attribute (view-class-slot-column s))
 197                                    (db-value-from-slot s val database))))
 198                        sds)))
 199     (cond ((and avps (view-database obj))
 200            (update-records (sql-expression :table vct)
 201                            :av-pairs avps
 202                            :where (key-qualifier-for-instance
 203                                    obj :database database)
 204                            :database database))
 205           ((and avps (not (view-database obj)))
 206            (insert-records :into (sql-expression :table vct)
 207                            :av-pairs avps
 208                            :database database)
 209            (setf (slot-value obj 'view-database) database))
 210           (t
 211            (error "Unable to update records"))))
 212   (values))
 213
 214 (defmethod update-records-from-instance ((obj standard-db-object) &key database)
 215   (let ((database (or database (view-database obj) *default-database*)))
 216     (labels ((slot-storedp (slot)
 217                (and (member (view-class-slot-db-kind slot) '(:base :key))
 218                     (slot-boundp obj (slot-definition-name slot))))
 219              (slot-value-list (slot)
 220                (let ((value (slot-value obj (slot-definition-name slot))))
 221                  (check-slot-type slot value)
 222                  (list (sql-expression :attribute (view-class-slot-column slot))
 223                        (db-value-from-slot slot value database)))))
 224       (let* ((view-class (class-of obj))
 225              (view-class-table (view-table view-class))
 226              (slots (remove-if-not #'slot-storedp
 227                                    (ordered-class-slots view-class)))
 228              (record-values (mapcar #'slot-value-list slots)))
 229         (unless record-values
 230           (error "No settable slots."))
 231         (if (view-database obj)
 232             (update-records (sql-expression :table view-class-table)
 233                             :av-pairs record-values
 234                             :where (key-qualifier-for-instance
 235                                     obj :database database)
 236                             :database database)
 237             (progn
 238               (insert-records :into (sql-expression :table view-class-table)
 239                               :av-pairs record-values
 240                               :database database)
 241               (setf (slot-value obj 'view-database) database))))))
 242   (values))
 243
 244 (defmethod delete-instance-records ((instance standard-db-object))
 245   (let ((vt (sql-expression :table (view-table (class-of instance))))
 246         (vd (view-database instance)))
 247     (if vd
 248         (let ((qualifier (key-qualifier-for-instance instance :database vd)))
 249           (delete-records :from vt :where qualifier :database vd)
 250           (setf (record-caches vd) nil)
 251           (setf (slot-value instance 'view-database) nil)
 252           (values))
 253         (signal-no-database-error vd))))
 254
 255 (defmethod update-instance-from-records ((instance standard-db-object)
 256                                          &key (database *default-database*))
 257   (let* ((view-class (find-class (class-name (class-of instance))))
 258          (view-table (sql-expression :table (view-table view-class)))
 259          (vd (or (view-database instance) database))
 260          (view-qual (key-qualifier-for-instance instance :database vd))
 261          (sels (generate-selection-list view-class))
 262          (res (apply #'select (append (mapcar #'cdr sels)
 263                                       (list :from  view-table
 264                                             :where view-qual
 265                                             :result-types nil
 266                                             :database vd)))))
 267     (when res
 268       (get-slot-values-from-view instance (mapcar #'car sels) (car res)))))
 269
 270 (defmethod update-slot-from-record ((instance standard-db-object)
 271                                     slot &key (database *default-database*))
 272   (let* ((view-class (find-class (class-name (class-of instance))))
 273          (view-table (sql-expression :table (view-table view-class)))
 274          (vd (or (view-database instance) database))
 275          (view-qual (key-qualifier-for-instance instance :database vd))
 276          (slot-def (slotdef-for-slot-with-class slot view-class))
 277          (att-ref (generate-attribute-reference view-class slot-def))
 278          (res (select att-ref :from  view-table :where view-qual
 279                       :result-types nil)))
 280     (when res
 281       (get-slot-values-from-view instance (list slot-def) (car res)))))
 282
 283
 284 (defmethod update-slot-with-null ((object standard-db-object)
 285                                   slotname
 286                                   slotdef)
 287   (setf (slot-value object slotname) (slot-value slotdef 'void-value)))
 288
 289 (defvar +no-slot-value+ '+no-slot-value+)
 290
 291 (defsql sql-slot-value (:symbol "slot-value") (classname slot &optional (value +no-slot-value+) (database *default-database*))
 292   (let* ((class (find-class classname))
 293          (sld (slotdef-for-slot-with-class slot class)))
 294     (if sld
 295         (if (eq value +no-slot-value+)
 296             (sql-expression :attribute (view-class-slot-column sld)
 297                             :table (view-table class))
 298             (db-value-from-slot
 299              sld
 300              value
 301              database))
 302         (error "Unknown slot ~A for class ~A" slot classname))))
 303
 304 (defsql sql-view-class (:symbol "view-class") (classname &optional (database *default-database*))
 305         (declare (ignore database))
 306         (let* ((class (find-class classname)))
 307           (unless (view-table class)
 308             (error "No view-table for class ~A"  classname))
 309           (sql-expression :table (view-table class))))
 310
 311
 312 (defmethod database-get-type-specifier (type args database db-type)
 313   (declare (ignore type args database db-type))
 314   (format nil "VARCHAR(~D)" *default-string-length*))
 315
 316 (defmethod database-get-type-specifier ((type (eql 'integer)) args database db-type)
 317   (declare (ignore database db-type))
 318   (if args
 319       (format nil "INT(~A)" (car args))
 320     "INT"))
 321
 322 (deftype tinyint ()
 323   "An 8-bit integer, this width may vary by SQL implementation."
 324   'integer)
 325
 326 (defmethod database-get-type-specifier ((type (eql 'tinyint)) args database db-type)
 327   (declare (ignore args database db-type))
 328   "INT")
 329
 330 (deftype smallint ()
 331   "An integer smaller than a 32-bit integer. this width may vary by SQL implementation."
 332   'integer)
 333
 334 (defmethod database-get-type-specifier ((type (eql 'smallint)) args database db-type)
 335   (declare (ignore args database db-type))
 336   "INT")
 337
 338 (deftype mediumint ()
 339   "An integer smaller than a 32-bit integer, but may be larger than a smallint. This width may vary by SQL implementation."
 340   'integer)
 341
 342 (defmethod database-get-type-specifier ((type (eql 'mediumint)) args database db-type)
 343   (declare (ignore args database db-type))
 344   "INT")
 345
 346 (deftype bigint ()
 347   "An integer larger than a 32-bit integer, this width may vary by SQL implementation."
 348   'integer)
 349
 350 (defmethod database-get-type-specifier ((type (eql 'bigint)) args database db-type)
 351   (declare (ignore args database db-type))
 352   "BIGINT")
 353
 354 (deftype varchar (&optional size)
 355   "A variable length string for the SQL varchar type."
 356   (declare (ignore size))
 357   'string)
 358
 359 (defmethod database-get-type-specifier ((type (eql 'varchar)) args
 360                                         database db-type)
 361   (declare (ignore database db-type))
 362   (if args
 363       (format nil "VARCHAR(~A)" (car args))
 364       (format nil "VARCHAR(~D)" *default-string-length*)))
 365
 366 (defmethod database-get-type-specifier ((type (eql 'string)) args database db-type)
 367   (declare (ignore database db-type))
 368   (if args
 369       (format nil "CHAR(~A)" (car args))
 370       (format nil "VARCHAR(~D)" *default-string-length*)))
 371
 372 (deftype universal-time ()
 373   "A positive integer as returned by GET-UNIVERSAL-TIME."
 374   '(integer 1 *))
 375
 376 (defmethod database-get-type-specifier ((type (eql 'universal-time)) args database db-type)
 377   (declare (ignore args database db-type))
 378   "BIGINT")
 379
 380 (defmethod database-get-type-specifier ((type (eql 'wall-time)) args database db-type)
 381   (declare (ignore args database db-type))
 382   "TIMESTAMP")
 383
 384 (defmethod database-get-type-specifier ((type (eql 'date)) args database db-type)
 385   (declare (ignore args database db-type))
 386   "DATE")
 387
 388 (defmethod database-get-type-specifier ((type (eql 'duration)) args database db-type)
 389   (declare (ignore database args db-type))
 390   "VARCHAR")
 391
 392 (defmethod database-get-type-specifier ((type (eql 'money)) args database db-type)
 393   (declare (ignore database args db-type))
 394   "INT8")
 395
 396 #+ignore
 397 (deftype char (&optional len)
 398   "A lisp type for the SQL CHAR type."
 399   `(string ,len))
 400
 401 (defmethod database-get-type-specifier ((type (eql 'float)) args database db-type)
 402   (declare (ignore database db-type))
 403   (if args
 404       (format nil "FLOAT(~A)" (car args))
 405       "FLOAT"))
 406
 407 (defmethod database-get-type-specifier ((type (eql 'long-float)) args database db-type)
 408   (declare (ignore database db-type))
 409   (if args
 410       (format nil "FLOAT(~A)" (car args))
 411       "FLOAT"))
 412
 413 (deftype generalized-boolean ()
 414   "A type which outputs a SQL boolean value, though any lisp type can be stored in the slot."
 415   t)
 416
 417 (defmethod database-get-type-specifier ((type (eql 'boolean)) args database db-type)
 418   (declare (ignore args database db-type))
 419   "BOOL")
 420
 421 (defmethod database-get-type-specifier ((type (eql 'generalized-boolean)) args database db-type)
 422   (declare (ignore args database db-type))
 423   "BOOL")
 424
 425 (defmethod database-get-type-specifier ((type (eql 'number)) args database db-type)
 426   (declare (ignore database db-type))
 427   (cond
 428    ((and (consp args) (= (length args) 2))
 429     (format nil "NUMBER(~D,~D)" (first args) (second args)))
 430    ((and (consp args) (= (length args) 1))
 431     (format nil "NUMBER(~D)" (first args)))
 432    (t
 433     "NUMBER")))
 434
 435 (defmethod database-get-type-specifier ((type (eql 'char)) args database db-type)
 436   (declare (ignore database db-type))
 437   (if args
 438       (format nil "CHAR(~D)" (first args))
 439       "CHAR(1)"))
 440
 441
 442 (defmethod database-output-sql-as-type (type val database db-type)
 443   (declare (ignore type database db-type))
 444   val)
 445
 446 (defmethod database-output-sql-as-type ((type (eql 'list)) val database db-type)
 447   (declare (ignore database db-type))
 448   (progv '(*print-circle* *print-array*) '(t t)
 449     (let ((escaped (prin1-to-string val)))
 450       (substitute-char-string
 451        escaped #\Null " "))))
 452
 453 (defmethod database-output-sql-as-type ((type (eql 'symbol)) val database db-type)
 454   (declare (ignore database db-type))
 455   (if val
 456     (concatenate 'string
 457                  (package-name (symbol-package val))
 458                  "::"
 459                  (symbol-name val))
 460     ""))
 461
 462 (defmethod database-output-sql-as-type ((type (eql 'keyword)) val database db-type)
 463   (declare (ignore database db-type))
 464   (if val
 465       (symbol-name val)
 466       ""))
 467
 468 (defmethod database-output-sql-as-type ((type (eql 'vector)) val database db-type)
 469   (declare (ignore database db-type))
 470   (progv '(*print-circle* *print-array*) '(t t)
 471     (prin1-to-string val)))
 472
 473 (defmethod database-output-sql-as-type ((type (eql 'array)) val database db-type)
 474   (declare (ignore database db-type))
 475   (progv '(*print-circle* *print-array*) '(t t)
 476     (prin1-to-string val)))
 477
 478 (defmethod database-output-sql-as-type ((type (eql 'boolean)) val database db-type)
 479   (declare (ignore database db-type))
 480   (if val "t" "f"))
 481
 482 (defmethod database-output-sql-as-type ((type (eql 'generalized-boolean)) val database db-type)
 483   (declare (ignore database db-type))
 484   (if val "t" "f"))
 485
 486 (defmethod database-output-sql-as-type ((type (eql 'string)) val database db-type)
 487   (declare (ignore database db-type))
 488   val)
 489
 490 (defmethod database-output-sql-as-type ((type (eql 'char)) val database db-type)
 491   (declare (ignore database db-type))
 492   (etypecase val
 493     (character (write-to-string val))
 494     (string val)))
 495
 496 (defmethod database-output-sql-as-type ((type (eql 'float)) val database db-type)
 497   (declare (ignore database db-type))
 498   (let ((*read-default-float-format* (type-of val)))
 499     (format nil "~F" val)))
 500
 501 (defmethod read-sql-value (val type database db-type)
 502   (declare (ignore type database db-type))
 503   (read-from-string val))
 504
 505 (defmethod read-sql-value (val (type (eql 'string)) database db-type)
 506   (declare (ignore database db-type))
 507   val)
 508
 509 (defmethod read-sql-value (val (type (eql 'varchar)) database db-type)
 510   (declare (ignore database db-type))
 511   val)
 512
 513 (defmethod read-sql-value (val (type (eql 'char)) database db-type)
 514   (declare (ignore database db-type))
 515   (schar val 0))
 516
 517 (defmethod read-sql-value (val (type (eql 'keyword)) database db-type)
 518   (declare (ignore database db-type))
 519   (when (< 0 (length val))
 520     (intern (symbol-name-default-case val)
 521             (find-package '#:keyword))))
 522
 523 (defmethod read-sql-value (val (type (eql 'symbol)) database db-type)
 524   (declare (ignore database db-type))
 525   (when (< 0 (length val))
 526     (unless (string= val (symbol-name-default-case "NIL"))
 527       (read-from-string val))))
 528
 529 (defmethod read-sql-value (val (type (eql 'integer)) database db-type)
 530   (declare (ignore database db-type))
 531   (etypecase val
 532     (string
 533      (unless (string-equal "NIL" val)
 534        (parse-integer val)))
 535     (number val)))
 536
 537 (defmethod read-sql-value (val (type (eql 'smallint)) database db-type)
 538   (declare (ignore database db-type))
 539   (etypecase val
 540     (string
 541      (unless (string-equal "NIL" val)
 542        (parse-integer val)))
 543     (number val)))
 544
 545 (defmethod read-sql-value (val (type (eql 'bigint)) database db-type)
 546   (declare (ignore database db-type))
 547   (etypecase val
 548     (string
 549      (unless (string-equal "NIL" val)
 550        (parse-integer val)))
 551     (number val)))
 552
 553 (defmethod read-sql-value (val (type (eql 'float)) database db-type)
 554   (declare (ignore database db-type))
 555   ;; writing 1.0 writes 1, so we we *really* want a float, must do (float ...)
 556   (etypecase val
 557     (string
 558      (float (read-from-string val)))
 559     (float
 560      val)))
 561
 562 (defmethod read-sql-value (val (type (eql 'boolean)) database db-type)
 563   (declare (ignore database db-type))
 564   (equal "t" val))
 565
 566 (defmethod read-sql-value (val (type (eql 'generalized-boolean)) database db-type)
 567   (declare (ignore database db-type))
 568   (equal "t" val))
 569
 570 (defmethod read-sql-value (val (type (eql 'number)) database db-type)
 571   (declare (ignore database db-type))
 572   (etypecase val
 573     (string
 574      (unless (string-equal "NIL" val)
 575        (read-from-string val)))
 576     (number val)))
 577
 578 (defmethod read-sql-value (val (type (eql 'universal-time)) database db-type)
 579   (declare (ignore database db-type))
 580   (unless (eq 'NULL val)
 581     (etypecase val
 582       (string
 583        (parse-integer val))
 584       (number val))))
 585
 586 (defmethod read-sql-value (val (type (eql 'wall-time)) database db-type)
 587   (declare (ignore database db-type))
 588   (unless (eq 'NULL val)
 589     (parse-timestring val)))
 590
 591 (defmethod read-sql-value (val (type (eql 'date)) database db-type)
 592   (declare (ignore database db-type))
 593   (unless (eq 'NULL val)
 594     (parse-datestring val)))
 595
 596 (defmethod read-sql-value (val (type (eql 'duration)) database db-type)
 597   (declare (ignore database db-type))
 598   (unless (or (eq 'NULL val)
 599               (equal "NIL" val))
 600     (parse-timestring val)))
 601
 602 ;; ------------------------------------------------------------
 603 ;; Logic for 'faulting in' :join slots
 604
 605 ;; this works, but is inefficient requiring (+ 1 n-rows)
 606 ;; SQL queries
 607 #+ignore
 608 (defun fault-join-target-slot (class object slot-def)
 609   (let* ((res (fault-join-slot-raw class object slot-def))
 610          (dbi (view-class-slot-db-info slot-def))
 611          (target-name (gethash :target-slot dbi))
 612          (target-class (find-class target-name)))
 613     (when res
 614       (mapcar (lambda (obj)
 615                 (list
 616                  (car
 617                   (fault-join-slot-raw
 618                    target-class
 619                    obj
 620                    (find target-name (class-slots (class-of obj))
 621                          :key #'slot-definition-name)))
 622                  obj))
 623               res)
 624       #+ignore ;; this doesn't work when attempting to call slot-value
 625       (mapcar (lambda (obj)
 626                 (cons obj (slot-value obj ts))) res))))
 627
 628 (defun fault-join-target-slot (class object slot-def)
 629   (let* ((dbi (view-class-slot-db-info slot-def))
 630          (ts (gethash :target-slot dbi))
 631          (jc  (gethash :join-class dbi))
 632          (jc-view-table (view-table (find-class jc)))
 633          (tdbi (view-class-slot-db-info
 634                 (find ts (class-slots (find-class jc))
 635                       :key #'slot-definition-name)))
 636          (retrieval (gethash :retrieval tdbi))
 637          (tsc (gethash :join-class tdbi))
 638          (ts-view-table (view-table (find-class tsc)))
 639          (jq (join-qualifier class object slot-def))
 640          (key (slot-value object (gethash :home-key dbi))))
 641
 642     (when jq
 643       (ecase retrieval
 644         (:immediate
 645          (let ((res
 646                 (find-all (list tsc)
 647                           :inner-join (sql-expression :table jc-view-table)
 648                           :on (sql-operation
 649                                '==
 650                                (sql-expression
 651                                 :attribute (gethash :foreign-key tdbi)
 652                                 :table ts-view-table)
 653                                (sql-expression
 654                                 :attribute (gethash :home-key tdbi)
 655                                 :table jc-view-table))
 656                           :where jq
 657                           :result-types :auto
 658                           :database (view-database object))))
 659            (mapcar #'(lambda (i)
 660                        (let* ((instance (car i))
 661                               (jcc (make-instance jc :view-database (view-database instance))))
 662                          (setf (slot-value jcc (gethash :foreign-key dbi))
 663                                key)
 664                          (setf (slot-value jcc (gethash :home-key tdbi))
 665                                (slot-value instance (gethash :foreign-key tdbi)))
 666                       (list instance jcc)))
 667                    res)))
 668         (:deferred
 669             ;; just fill in minimal slots
 670             (mapcar
 671              #'(lambda (k)
 672                  (let ((instance (make-instance tsc :view-database (view-database object)))
 673                        (jcc (make-instance jc :view-database (view-database object)))
 674                        (fk (car k)))
 675                    (setf (slot-value instance (gethash :home-key tdbi)) fk)
 676                    (setf (slot-value jcc (gethash :foreign-key dbi))
 677                          key)
 678                    (setf (slot-value jcc (gethash :home-key tdbi))
 679                          fk)
 680                    (list instance jcc)))
 681              (select (sql-expression :attribute (gethash :foreign-key tdbi) :table jc-view-table)
 682                      :from (sql-expression :table jc-view-table)
 683                      :where jq
 684                      :database (view-database object))))))))
 685
 686
 687 ;;; Remote Joins
 688
 689 (defvar *default-update-objects-max-len* nil
 690   "The default value to use for the MAX-LEN keyword argument to
 691   UPDATE-OBJECT-JOINS.")
 692
 693 (defun update-objects-joins (objects &key (slots t) (force-p t)
 694                             class-name (max-len
 695                             *default-update-objects-max-len*))
 696   "Updates from the records of the appropriate database tables
 697 the join slots specified by SLOTS in the supplied list of View
 698 Class instances OBJECTS.  SLOTS is t by default which means that
 699 all join slots with :retrieval :immediate are updated. CLASS-NAME
 700 is used to specify the View Class of all instance in OBJECTS and
 701 default to nil which means that the class of the first instance
 702 in OBJECTS is used. FORCE-P is t by default which means that all
 703 join slots are updated whereas a value of nil means that only
 704 unbound join slots are updated. MAX-LEN defaults to
 705 *DEFAULT-UPDATE-OBJECTS-MAX-LEN* and when non-nil specifies that
 706 UPDATE-OBJECT-JOINS may issue multiple database queries with a
 707 maximum of MAX-LEN instances updated in each query."
 708   (assert (or (null max-len) (plusp max-len)))
 709   (when objects
 710     (unless class-name
 711       (setq class-name (class-name (class-of (first objects)))))
 712     (let* ((class (find-class class-name))
 713            (class-slots (ordered-class-slots class))
 714            (slotdefs
 715             (if (eq t slots)
 716                 (generate-retrieval-joins-list class :deferred)
 717               (remove-if #'null
 718                          (mapcar #'(lambda (name)
 719                                      (let ((slotdef (find name class-slots :key #'slot-definition-name)))
 720                                        (unless slotdef
 721                                          (warn "Unable to find slot named ~S in class ~S." name class))
 722                                        slotdef))
 723                                  slots)))))
 724       (dolist (slotdef slotdefs)
 725         (let* ((dbi (view-class-slot-db-info slotdef))
 726                (slotdef-name (slot-definition-name slotdef))
 727                (foreign-key (gethash :foreign-key dbi))
 728                (home-key (gethash :home-key dbi))
 729                (object-keys
 730                 (remove-duplicates
 731                  (if force-p
 732                      (mapcar #'(lambda (o) (slot-value o home-key)) objects)
 733                    (remove-if #'null
 734                               (mapcar
 735                                #'(lambda (o) (if (slot-boundp o slotdef-name)
 736                                                  nil
 737                                                (slot-value o home-key)))
 738                                objects)))))
 739                (n-object-keys (length object-keys))
 740                (query-len (or max-len n-object-keys)))
 741
 742           (do ((i 0 (+ i query-len)))
 743               ((>= i n-object-keys))
 744             (let* ((keys (if max-len
 745                              (subseq object-keys i (min (+ i query-len) n-object-keys))
 746                            object-keys))
 747                    (results (unless (gethash :target-slot dbi)
 748                                 (find-all (list (gethash :join-class dbi))
 749                               :where (make-instance 'sql-relational-exp
 750                                                     :operator 'in
 751                                                     :sub-expressions (list (sql-expression :attribute foreign-key)
 752                                                                            keys))
 753                               :result-types :auto
 754                               :flatp t)) ))
 755
 756               (dolist (object objects)
 757                 (when (or force-p (not (slot-boundp object slotdef-name)))
 758                   (let ((res (if results
 759                                  (remove-if-not #'(lambda (obj)
 760                                                     (equal obj (slot-value
 761                                                                 object
 762                                                                 home-key)))
 763                                                 results
 764                                                 :key #'(lambda (res)
 765                                                          (slot-value res
 766                                                                      foreign-key)))
 767
 768                                  (progn
 769                                    (when (gethash :target-slot dbi)
 770                                      (fault-join-target-slot class object slotdef))))))
 771                     (when res
 772                       (setf (slot-value object slotdef-name)
 773                             (if (gethash :set dbi) res (car res)))))))))))))
 774   (values))
 775
 776 (defun fault-join-slot-raw (class object slot-def)
 777   (let* ((dbi (view-class-slot-db-info slot-def))
 778          (jc (gethash :join-class dbi)))
 779     (let ((jq (join-qualifier class object slot-def)))
 780       (when jq
 781         (select jc :where jq :flatp t :result-types nil
 782                 :database (view-database object))))))
 783
 784 (defun fault-join-slot (class object slot-def)
 785   (let* ((dbi (view-class-slot-db-info slot-def))
 786          (ts (gethash :target-slot dbi)))
 787     (if (and ts (gethash :set dbi))
 788         (fault-join-target-slot class object slot-def)
 789         (let ((res (fault-join-slot-raw class object slot-def)))
 790           (when res
 791             (cond
 792               ((and ts (not (gethash :set dbi)))
 793                (mapcar (lambda (obj) (slot-value obj ts)) res))
 794               ((and (not ts) (not (gethash :set dbi)))
 795                (car res))
 796               ((and (not ts) (gethash :set dbi))
 797                res)))))))
 798
 799 (defun join-qualifier (class object slot-def)
 800     (declare (ignore class))
 801     (let* ((dbi (view-class-slot-db-info slot-def))
 802            (jc (find-class (gethash :join-class dbi)))
 803            ;;(ts (gethash :target-slot dbi))
 804            ;;(tsdef (if ts (slotdef-for-slot-with-class ts jc)))
 805            (foreign-keys (gethash :foreign-key dbi))
 806            (home-keys (gethash :home-key dbi)))
 807       (when (every #'(lambda (slt)
 808                        (and (slot-boundp object slt)
 809                             (not (null (slot-value object slt)))))
 810                    (if (listp home-keys) home-keys (list home-keys)))
 811         (let ((jc
 812                (mapcar #'(lambda (hk fk)
 813                            (let ((fksd (slotdef-for-slot-with-class fk jc)))
 814                              (sql-operation '==
 815                                             (typecase fk
 816                                               (symbol
 817                                                (sql-expression
 818                                                 :attribute
 819                                                 (view-class-slot-column fksd)
 820                                                 :table (view-table jc)))
 821                                               (t fk))
 822                                             (typecase hk
 823                                               (symbol
 824                                                (slot-value object hk))
 825                                               (t
 826                                                hk)))))
 827                        (if (listp home-keys)
 828                            home-keys
 829                            (list home-keys))
 830                        (if (listp foreign-keys)
 831                            foreign-keys
 832                            (list foreign-keys)))))
 833           (when jc
 834             (if (> (length jc) 1)
 835                 (apply #'sql-and jc)
 836                 jc))))))
 837
 838 ;; FIXME: add retrieval immediate for efficiency
 839 ;; For example, for (select 'employee-address) in test suite =>
 840 ;; select addr.*,ea_join.* FROM addr,ea_join WHERE ea_join.aaddressid=addr.addressid\g
 841
 842 (defun build-objects (vals sclasses immediate-join-classes sels immediate-joins database refresh flatp instances)
 843   "Used by find-all to build objects."
 844   (labels ((build-object (vals vclass jclasses selects immediate-selects instance)
 845              (let* ((db-vals (butlast vals (- (list-length vals)
 846                                               (list-length selects))))
 847                     (obj (if instance instance (make-instance (class-name vclass) :view-database database)))
 848                     (join-vals (subseq vals (list-length selects)))
 849                     (joins (mapcar #'(lambda (c) (when c (make-instance c :view-database database)))
 850                                    jclasses)))
 851
 852                ;;(format t "joins: ~S~%db-vals: ~S~%join-values: ~S~%selects: ~S~%immediate-selects: ~S~%"
 853                ;;joins db-vals join-vals selects immediate-selects)
 854
 855                ;; use refresh keyword here
 856                (setf obj (get-slot-values-from-view obj (mapcar #'car selects) db-vals))
 857                (mapc #'(lambda (jo)
 858                          ;; find all immediate-select slots and join-vals for this object
 859                          (let* ((slots (class-slots (class-of jo)))
 860                                 (pos-list (remove-if #'null
 861                                                      (mapcar
 862                                                       #'(lambda (s)
 863                                                           (position s immediate-selects
 864                                                                     :key #'car
 865                                                                     :test #'eq))
 866                                                       slots))))
 867                            (get-slot-values-from-view jo
 868                                                       (mapcar #'car
 869                                                               (mapcar #'(lambda (pos)
 870                                                                           (nth pos immediate-selects))
 871                                                                       pos-list))
 872                                                       (mapcar #'(lambda (pos) (nth pos join-vals))
 873                                                               pos-list))))
 874                      joins)
 875                (mapc
 876                 #'(lambda (jc)
 877                     (let ((slot (find (class-name (class-of jc)) (class-slots vclass)
 878                                       :key #'(lambda (slot)
 879                                                (when (and (eq :join (view-class-slot-db-kind slot))
 880                                                           (eq (slot-definition-name slot)
 881                                                               (gethash :join-class (view-class-slot-db-info slot))))
 882                                                  (slot-definition-name slot))))))
 883                       (when slot
 884                         (setf (slot-value obj (slot-definition-name slot)) jc))))
 885                 joins)
 886                (when refresh (instance-refreshed obj))
 887                obj)))
 888     (let* ((objects
 889             (mapcar #'(lambda (sclass jclass sel immediate-join instance)
 890                         (prog1
 891                             (build-object vals sclass jclass sel immediate-join instance)
 892                           (setf vals (nthcdr (+ (list-length sel) (list-length immediate-join))
 893                                              vals))))
 894                     sclasses immediate-join-classes sels immediate-joins instances)))
 895       (if (and flatp (= (length sclasses) 1))
 896           (car objects)
 897         objects))))
 898
 899 (defun find-all (view-classes
 900                  &rest args
 901                  &key all set-operation distinct from where group-by having
 902                       order-by offset limit refresh flatp result-types
 903                       inner-join on
 904                       (database *default-database*)
 905                       instances)
 906   "Called by SELECT to generate object query results when the
 907   View Classes VIEW-CLASSES are passed as arguments to SELECT."
 908   (declare (ignore all set-operation group-by having offset limit inner-join on))
 909   (flet ((ref-equal (ref1 ref2)
 910            (string= (sql-output ref1 database)
 911                     (sql-output ref2 database)))
 912          (table-sql-expr (table)
 913            (sql-expression :table (view-table table)))
 914          (tables-equal (table-a table-b)
 915            (when (and table-a table-b)
 916              (string= (string (slot-value table-a 'name))
 917                       (string (slot-value table-b 'name))))))
 918     (remf args :from)
 919     (remf args :where)
 920     (remf args :flatp)
 921     (remf args :additional-fields)
 922     (remf args :result-types)
 923     (remf args :instances)
 924     (let* ((*db-deserializing* t)
 925            (sclasses (mapcar #'find-class view-classes))
 926            (immediate-join-slots
 927             (mapcar #'(lambda (c) (generate-retrieval-joins-list c :immediate)) sclasses))
 928            (immediate-join-classes
 929             (mapcar #'(lambda (jcs)
 930                         (mapcar #'(lambda (slotdef)
 931                                     (find-class (gethash :join-class (view-class-slot-db-info slotdef))))
 932                                 jcs))
 933                     immediate-join-slots))
 934            (immediate-join-sels (mapcar #'generate-immediate-joins-selection-list sclasses))
 935            (sels (mapcar #'generate-selection-list sclasses))
 936            (fullsels (apply #'append (mapcar #'append sels immediate-join-sels)))
 937            (sel-tables (collect-table-refs where))
 938            (tables (remove-if #'null
 939                               (remove-duplicates
 940                                (append (mapcar #'table-sql-expr sclasses)
 941                                        (mapcan #'(lambda (jc-list)
 942                                                    (mapcar
 943                                                     #'(lambda (jc) (when jc (table-sql-expr jc)))
 944                                                     jc-list))
 945                                                immediate-join-classes)
 946                                        sel-tables)
 947                                :test #'tables-equal)))
 948            (order-by-slots (mapcar #'(lambda (ob) (if (atom ob) ob (car ob)))
 949                                    (listify order-by)))
 950            (join-where nil))
 951
 952       ;;(format t "sclasses: ~W~%ijc: ~W~%tables: ~W~%" sclasses immediate-join-classes tables)
 953
 954       (dolist (ob order-by-slots)
 955         (when (and ob (not (member ob (mapcar #'cdr fullsels)
 956                                    :test #'ref-equal)))
 957           (setq fullsels
 958             (append fullsels (mapcar #'(lambda (att) (cons nil att))
 959                                      order-by-slots)))))
 960       (dolist (ob (listify distinct))
 961         (when (and (typep ob 'sql-ident)
 962                    (not (member ob (mapcar #'cdr fullsels)
 963                                 :test #'ref-equal)))
 964           (setq fullsels
 965               (append fullsels (mapcar #'(lambda (att) (cons nil att))
 966                                        (listify ob))))))
 967       (mapcar #'(lambda (vclass jclasses jslots)
 968                   (when jclasses
 969                     (mapcar
 970                      #'(lambda (jclass jslot)
 971                          (let ((dbi (view-class-slot-db-info jslot)))
 972                            (setq join-where
 973                              (append
 974                               (list (sql-operation '==
 975                                                    (sql-expression
 976                                                     :attribute (gethash :foreign-key dbi)
 977                                                     :table (view-table jclass))
 978                                                    (sql-expression
 979                                                     :attribute (gethash :home-key dbi)
 980                                                     :table (view-table vclass))))
 981                               (when join-where (listify join-where))))))
 982                      jclasses jslots)))
 983               sclasses immediate-join-classes immediate-join-slots)
 984       ;; Reported buggy on clsql-devel
 985       ;; (when where (setq where (listify where)))
 986       (cond
 987        ((and where join-where)
 988         (setq where (list (apply #'sql-and where join-where))))
 989        ((and (null where) (> (length join-where) 1))
 990         (setq where (list (apply #'sql-and join-where)))))
 991
 992       (let* ((rows (apply #'select
 993                           (append (mapcar #'cdr fullsels)
 994                                   (cons :from
 995                                         (list (append (when from (listify from))
 996                                                       (listify tables))))
 997                                   (list :result-types result-types)
 998                                   (when where
 999                                     (list :where where))
1000                                   args)))
1001              (instances-to-add (- (length rows) (length instances)))
1002              (perhaps-extended-instances
1003               (if (plusp instances-to-add)
1004                   (append instances (do ((i 0 (1+ i))
1005                                          (res nil))
1006                                         ((= i instances-to-add) res)
1007                                       (push (make-list (length sclasses) :initial-element nil) res)))
1008                 instances))
1009              (objects (mapcar
1010                        #'(lambda (row instance)
1011                            (build-objects row sclasses immediate-join-classes sels
1012                                           immediate-join-sels database refresh flatp
1013                                           (if (and flatp (atom instance))
1014                                               (list instance)
1015                                             instance)))
1016                        rows perhaps-extended-instances)))
1017         objects))))
1018
1019 (defmethod instance-refreshed ((instance standard-db-object)))
1020
1021 (defvar *default-caching* t
1022   "Controls whether SELECT caches objects by default. The CommonSQL
1023 specification states caching is on by default.")
1024
1025 (defun select (&rest select-all-args)
1026    "Executes a query on DATABASE, which has a default value of
1027 *DEFAULT-DATABASE*, specified by the SQL expressions supplied
1028 using the remaining arguments in SELECT-ALL-ARGS. The SELECT
1029 argument can be used to generate queries in both functional and
1030 object oriented contexts.
1031
1032 In the functional case, the required arguments specify the
1033 columns selected by the query and may be symbolic SQL expressions
1034 or strings representing attribute identifiers. Type modified
1035 identifiers indicate that the values selected from the specified
1036 column are converted to the specified lisp type. The keyword
1037 arguments ALL, DISTINCT, FROM, GROUP-by, HAVING, ORDER-BY,
1038 SET-OPERATION and WHERE are used to specify, using the symbolic
1039 SQL syntax, the corresponding components of the SQL query
1040 generated by the call to SELECT. RESULT-TYPES is a list of
1041 symbols which specifies the lisp type for each field returned by
1042 the query. If RESULT-TYPES is nil all results are returned as
1043 strings whereas the default value of :auto means that the lisp
1044 types are automatically computed for each field. FIELD-NAMES is t
1045 by default which means that the second value returned is a list
1046 of strings representing the columns selected by the query. If
1047 FIELD-NAMES is nil, the list of column names is not returned as a
1048 second value.
1049
1050 In the object oriented case, the required arguments to SELECT are
1051 symbols denoting View Classes which specify the database tables
1052 to query. In this case, SELECT returns a list of View Class
1053 instances whose slots are set from the attribute values of the
1054 records in the specified table. Slot-value is a legal operator
1055 which can be employed as part of the symbolic SQL syntax used in
1056 the WHERE keyword argument to SELECT. REFRESH is nil by default
1057 which means that the View Class instances returned are retrieved
1058 from a cache if an equivalent call to SELECT has previously been
1059 issued. If REFRESH is true, the View Class instances returned are
1060 updated as necessary from the database and the generic function
1061 INSTANCE-REFRESHED is called to perform any necessary operations
1062 on the updated instances.
1063
1064 In both object oriented and functional contexts, FLATP has a
1065 default value of nil which means that the results are returned as
1066 a list of lists. If FLATP is t and only one result is returned
1067 for each record selected in the query, the results are returned
1068 as elements of a list."
1069
1070    (flet ((select-objects (target-args)
1071             (and target-args
1072                  (every #'(lambda (arg)
1073                             (and (symbolp arg)
1074                                  (find-class arg nil)))
1075                         target-args))))
1076      (multiple-value-bind (target-args qualifier-args)
1077          (query-get-selections select-all-args)
1078        (unless (or *default-database* (getf qualifier-args :database))
1079          (signal-no-database-error nil))
1080
1081        (cond
1082          ((select-objects target-args)
1083           (let ((caching (getf qualifier-args :caching *default-caching*))
1084                 (result-types (getf qualifier-args :result-types :auto))
1085                 (refresh (getf qualifier-args :refresh nil))
1086                 (database (or (getf qualifier-args :database) *default-database*))
1087                 (order-by (getf qualifier-args :order-by)))
1088             (remf qualifier-args :caching)
1089             (remf qualifier-args :refresh)
1090             (remf qualifier-args :result-types)
1091
1092             ;; Add explicity table name to order-by if not specified and only
1093             ;; one selected table. This is required so FIND-ALL won't duplicate
1094             ;; the field
1095             (when (and order-by (= 1 (length target-args)))
1096               (let ((table-name (view-table (find-class (car target-args))))
1097                     (order-by-list (copy-seq (listify order-by))))
1098
1099                 (loop for i from 0 below (length order-by-list)
1100                       do (etypecase (nth i order-by-list)
1101                            (sql-ident-attribute
1102                             (unless (slot-value (nth i order-by-list) 'qualifier)
1103                               (setf (slot-value (nth i order-by-list) 'qualifier) table-name)))
1104                            (cons
1105                             (unless (slot-value (car (nth i order-by-list)) 'qualifier)
1106                               (setf (slot-value (car (nth i order-by-list)) 'qualifier) table-name)))))
1107                 (setf (getf qualifier-args :order-by) order-by-list)))
1108
1109             (cond
1110               ((null caching)
1111                (apply #'find-all target-args
1112                       (append qualifier-args
1113                               (list :result-types result-types :refresh refresh))))
1114               (t
1115                (let ((cached (records-cache-results target-args qualifier-args database)))
1116                  (cond
1117                    ((and cached (not refresh))
1118                     cached)
1119                    ((and cached refresh)
1120                     (let ((results (apply #'find-all (append (list target-args) qualifier-args `(:instances ,cached :result-types :auto :refresh ,refresh)))))
1121                       (setf (records-cache-results target-args qualifier-args database) results)
1122                       results))
1123                    (t
1124                     (let ((results (apply #'find-all target-args (append qualifier-args
1125                                                                          `(:result-types :auto :refresh ,refresh)))))
1126                       (setf (records-cache-results target-args qualifier-args database) results)
1127                       results))))))))
1128          (t
1129           (let* ((expr (apply #'make-query select-all-args))
1130                  (specified-types
1131                   (mapcar #'(lambda (attrib)
1132                               (if (typep attrib 'sql-ident-attribute)
1133                                   (let ((type (slot-value attrib 'type)))
1134                                     (if type
1135                                         type
1136                                         t))
1137                                   t))
1138                           (slot-value expr 'selections))))
1139             (destructuring-bind (&key (flatp nil)
1140                                       (result-types :auto)
1141                                       (field-names t)
1142                                       (database *default-database*)
1143                                       &allow-other-keys)
1144                 qualifier-args
1145               (query expr :flatp flatp
1146                      :result-types
1147                      ;; specifying a type for an attribute overrides result-types
1148                      (if (some #'(lambda (x) (not (eq t x))) specified-types)
1149                          specified-types
1150                          result-types)
1151                      :field-names field-names
1152                      :database database))))))))
1153
1154 (defun compute-records-cache-key (targets qualifiers)
1155   (list targets
1156         (do ((args *select-arguments* (cdr args))
1157              (results nil))
1158             ((null args) results)
1159           (let* ((arg (car args))
1160                  (value (getf qualifiers arg)))
1161             (when value
1162               (push (list arg
1163                           (typecase value
1164                             (cons (cons (sql (car value)) (cdr value)))
1165                             (%sql-expression (sql value))
1166                             (t value)))
1167                     results))))))
1168
1169 (defun records-cache-results (targets qualifiers database)
1170   (when (record-caches database)
1171     (gethash (compute-records-cache-key targets qualifiers) (record-caches database))))
1172
1173 (defun (setf records-cache-results) (results targets qualifiers database)
1174   (unless (record-caches database)
1175     (setf (record-caches database)
1176           (make-hash-table :test 'equal
1177                            #+allegro   :values    #+allegro :weak
1178                            #+clisp     :weak      #+clisp :value
1179                            #+lispworks :weak-kind #+lispworks :value)))
1180   (setf (gethash (compute-records-cache-key targets qualifiers)
1181                  (record-caches database)) results)
1182   results)
1183
1184
1185
1186 ;;; Serialization functions
1187
1188 (defun write-instance-to-stream (obj stream)
1189   "Writes an instance to a stream where it can be later be read.
1190 NOTE: an error will occur if a slot holds a value which can not be written readably."
1191   (let* ((class (class-of obj))
1192          (alist '()))
1193     (dolist (slot (ordered-class-slots (class-of obj)))
1194       (let ((name (slot-definition-name slot)))
1195         (when (and (not (eq 'view-database name))
1196                    (slot-boundp obj name))
1197           (push (cons name (slot-value obj name)) alist))))
1198     (setq alist (reverse alist))
1199     (write (cons (class-name class) alist) :stream stream :readably t))
1200   obj)
1201
1202 (defun read-instance-from-stream (stream)
1203   (let ((raw (read stream nil nil)))
1204     (when raw
1205       (let ((obj (make-instance (car raw))))
1206         (dolist (pair (cdr raw))
1207           (setf (slot-value obj (car pair)) (cdr pair)))
1208         obj))))