Databases
StackOverflow2013
Postsdbo
POUsing a defstruct database with remove-if-not
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POUsing a defstruct database with remove-if-not
    primarykey
    data
    text
    <p>I'm trying to adapt this <a href="http://mypage.iu.edu/~colallen/lp/node56.html" rel="nofollow noreferrer">defstruct</a> example by adding the <strong>select-</strong> functions described in the book: <a href="http://www.gigamonkeys.com/book/practical-a-simple-database.html" rel="nofollow noreferrer">Practical Common Lisp</a>. I'm running the code in Emacs using the Common Lisp package. The <strong>select-by-first</strong> does not return anything. In the Lisp book, the author does not use defstruct so I must need to do something slightly different?</p> <pre> (defun <strong>select-by-first</strong> (first-name) (remove-if-not #'(lambda (employee) (equal (getf employee :first-name) first-name)) *emp-db*)) (select-by-first "steve") </pre> <p>The complete program:</p> <pre><code>(require 'cl) ;; http://mypage.iu.edu/~colallen/lp/node56.html ;; http://www.gigamonkeys.com/book/practical-a-simple-database.html ;; (defvar *emp-db* nil) (defun add-record (emp) (push emp *emp-db*)) (defstruct employee age first-name last-name sex children)</code> </pre> <pre> <code>(add-record (make-employee)) (add-record (make-employee :age 34 :last-name 'farquharson :first-name 'alice :sex 'female)) (add-record (make-employee :age 43 :last-name 'jobs :first-name 'steve :sex 'male)) (add-record (make-employee :age 53 :last-name 'ballmer :first-name 'steve :sex 'male))</code> </pre> <pre> <code>(defun select-by-first (first-name) (remove-if-not #'(lambda (employee) (equal (getf employee :first-name) first-name)) *emp-db*)) (select-by-first "steve")</code> </pre>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USRainer Joswig
    1. This table or related slice is empty.
    plurals
    1. This table or related slice is empty.
    1. PL
      singulars
      1. LTLinked
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POUsing a defstruct database with remove-if-not
      1. This table or related slice is empty.
      1. VTUpMod
    1. This table or related slice is empty.
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload