Skip to content
  • Categories
  • Recent
  • Tags
  • Popular
  • World
  • Users
  • Groups
Skins
  • Light
  • Cerulean
  • Cosmo
  • Flatly
  • Journal
  • Litera
  • Lumen
  • Lux
  • Materia
  • Minty
  • Morph
  • Pulse
  • Sandstone
  • Simplex
  • Sketchy
  • Spacelab
  • United
  • Yeti
  • Zephyr
  • Dark
  • Cyborg
  • Darkly
  • Quartz
  • Slate
  • Solar
  • Superhero
  • Vapor

  • Default (No Skin)
  • No Skin
Collapse
Code Project
CODE PROJECT For Those Who Code
  • Home
  • Articles
  • FAQ
Community
  1. Home
  2. General Programming
  3. C / C++ / MFC
  4. what is zed doing here?

what is zed doing here?

Scheduled Pinned Locked Moved C / C++ / MFC
databasequestion
11 Posts 4 Posters 0 Views 1 Watching
  • Oldest to Newest
  • Newest to Oldest
  • Most Votes
Reply
  • Reply as topic
Log in to reply
This topic has been deleted. Only users with topic management privileges can see it.
  • A Offline
    A Offline
    Alex Sturza
    wrote on last edited by
    #1

    in this code?from where i need to understand that is deleting something? void Database_delete(struct Connection *conn, int id) { struct Address addr = {.id = id, .set = 0}; conn->db->rows[id] = addr;

    CPalliniC J P 3 Replies Last reply
    0
    • A Alex Sturza

      in this code?from where i need to understand that is deleting something? void Database_delete(struct Connection *conn, int id) { struct Address addr = {.id = id, .set = 0}; conn->db->rows[id] = addr;

      CPalliniC Offline
      CPalliniC Offline
      CPallini
      wrote on last edited by
      #2

      As far as I know, this is not valid C++ code.

      THESE PEOPLE REALLY BOTHER ME!! How can they know what you should do without knowing what you want done?!?! -- C++ FQA Lite

      In testa che avete, signor di Ceprano?

      A 1 Reply Last reply
      0
      • CPalliniC CPallini

        As far as I know, this is not valid C++ code.

        THESE PEOPLE REALLY BOTHER ME!! How can they know what you should do without knowing what you want done?!?! -- C++ FQA Lite

        A Offline
        A Offline
        Alex Sturza
        wrote on last edited by
        #3

        this is C code!!!

        CPalliniC 1 Reply Last reply
        0
        • A Alex Sturza

          in this code?from where i need to understand that is deleting something? void Database_delete(struct Connection *conn, int id) { struct Address addr = {.id = id, .set = 0}; conn->db->rows[id] = addr;

          J Offline
          J Offline
          jeron1
          wrote on last edited by
          #4

          This[^] thread might help. It looks as though there are members of the Address struct one called set and it's getting initialized to 0, and another called id and it's getting initialized to the given integer id.

          "the debugger doesn't tell me anything because this code compiles just fine" - random QA comment "Facebook is where you tell lies to your friends. Twitter is where you tell the truth to strangers." - chriselst

          A 1 Reply Last reply
          0
          • J jeron1

            This[^] thread might help. It looks as though there are members of the Address struct one called set and it's getting initialized to 0, and another called id and it's getting initialized to the given integer id.

            "the debugger doesn't tell me anything because this code compiles just fine" - random QA comment "Facebook is where you tell lies to your friends. Twitter is where you tell the truth to strangers." - chriselst

            A Offline
            A Offline
            Alex Sturza
            wrote on last edited by
            #5

            yes,but by the name of function says(database_delete),this function must delete something,and i don't know how it is deleting something

            J 1 Reply Last reply
            0
            • A Alex Sturza

              yes,but by the name of function says(database_delete),this function must delete something,and i don't know how it is deleting something

              J Offline
              J Offline
              jeron1
              wrote on last edited by
              #6

              Just a guess, perhaps set is some kind of flag marking a record as inactive or something, as opposed to actually deleting a record. What a functions name is and what it actually does may be two different things. What's needed here I believe is some useful comments.

              "the debugger doesn't tell me anything because this code compiles just fine" - random QA comment "Facebook is where you tell lies to your friends. Twitter is where you tell the truth to strangers." - chriselst

              A 1 Reply Last reply
              0
              • J jeron1

                Just a guess, perhaps set is some kind of flag marking a record as inactive or something, as opposed to actually deleting a record. What a functions name is and what it actually does may be two different things. What's needed here I believe is some useful comments.

                "the debugger doesn't tell me anything because this code compiles just fine" - random QA comment "Facebook is where you tell lies to your friends. Twitter is where you tell the truth to strangers." - chriselst

                A Offline
                A Offline
                Alex Sturza
                wrote on last edited by
                #7

                can i give you the entire code?maybe you will find my answer:)

                1 Reply Last reply
                0
                • A Alex Sturza

                  in this code?from where i need to understand that is deleting something? void Database_delete(struct Connection *conn, int id) { struct Address addr = {.id = id, .set = 0}; conn->db->rows[id] = addr;

                  P Offline
                  P Offline
                  Pete OHanlon
                  wrote on last edited by
                  #8

                  This ties into the code you posted below. Specifically, it's related to this method:

                  void Database_set(struct Connection *conn, int id, const char *name, const char *email)
                  {
                  struct Address *addr = &conn->db->rows[id];
                  if(addr->set) die("Already set, delete it first");

                  addr->set = 1;

                  Basically, it looks like it's controlling whether or not you've already set the value in this row - so, to set a value here, you would call Database_delete first, which changes the value in id from 1 to 0, which means that the rest of Database_set can continue.

                  A 1 Reply Last reply
                  0
                  • A Alex Sturza

                    this is C code!!!

                    CPalliniC Offline
                    CPalliniC Offline
                    CPallini
                    wrote on last edited by
                    #9

                    Yes, you are right. :-O

                    THESE PEOPLE REALLY BOTHER ME!! How can they know what you should do without knowing what you want done?!?! -- C++ FQA Lite

                    In testa che avete, signor di Ceprano?

                    1 Reply Last reply
                    0
                    • P Pete OHanlon

                      This ties into the code you posted below. Specifically, it's related to this method:

                      void Database_set(struct Connection *conn, int id, const char *name, const char *email)
                      {
                      struct Address *addr = &conn->db->rows[id];
                      if(addr->set) die("Already set, delete it first");

                      addr->set = 1;

                      Basically, it looks like it's controlling whether or not you've already set the value in this row - so, to set a value here, you would call Database_delete first, which changes the value in id from 1 to 0, which means that the rest of Database_set can continue.

                      A Offline
                      A Offline
                      Alex Sturza
                      wrote on last edited by
                      #10

                      i understand now,thank you very much!

                      P 1 Reply Last reply
                      0
                      • A Alex Sturza

                        i understand now,thank you very much!

                        P Offline
                        P Offline
                        Pete OHanlon
                        wrote on last edited by
                        #11

                        You're welcome. :-D

                        1 Reply Last reply
                        0
                        Reply
                        • Reply as topic
                        Log in to reply
                        • Oldest to Newest
                        • Newest to Oldest
                        • Most Votes


                        • Login

                        • Don't have an account? Register

                        • Login or register to search.
                        • First post
                          Last post
                        0
                        • Categories
                        • Recent
                        • Tags
                        • Popular
                        • World
                        • Users
                        • Groups