Skip to content
  • Categories
  • Recent
  • Tags
  • Popular
  • Users
  • Groups
  • Search
  • Get Qt Extensions
  • Unsolved
Collapse
Brand Logo
  1. Home
  2. Qt Development
  3. General and Desktop
  4. Selecting data from mysql using qt?
Forum Update on Monday, May 27th 2025

Selecting data from mysql using qt?

Scheduled Pinned Locked Moved General and Desktop
150 Posts 7 Posters 142.1k Views
  • 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.
  • L Offline
    L Offline
    lyuts
    wrote on 12 Oct 2010, 09:18 last edited by
    #43

    Cut it into pieces or use something like pastebin.

    I'm a rebel in the S.D.G.

    1 Reply Last reply
    0
    • D Offline
      D Offline
      doforumda
      wrote on 12 Oct 2010, 09:21 last edited by
      #44

      ok here it is
      @
      root@zafar-laptop:/# /opt/lampp/bin/mysql -u root -p 123456 testTwo
      /opt/lampp/bin/mysql Ver 14.14 Distrib 5.1.41, for pc-linux-gnu (i686) using EditLine wrapper
      Copyright 2000-2008 MySQL AB, 2008 Sun Microsystems, Inc.
      This software comes with ABSOLUTELY NO WARRANTY. This is free software,
      and you are welcome to modify and redistribute it under the GPL license
      Usage: /opt/lampp/bin/mysql [OPTIONS] [database]
      -?, --help Display this help and exit.
      -I, --help Synonym for -?
      --auto-rehash Enable automatic rehashing. One doesn't need to use
      'rehash' to get table and field completion, but startup
      and reconnecting may take a longer time. Disable with
      --disable-auto-rehash.
      -A, --no-auto-rehash
      No automatic rehashing. One has to use 'rehash' to get
      table and field completion. This gives a quicker start of
      mysql and disables rehashing on reconnect. WARNING:
      options deprecated; use --disable-auto-rehash instead.
      -B, --batch Don't use history file. Disable interactive behavior.
      (Enables --silent)
      --character-sets-dir=name
      Directory where character sets are.
      --column-type-info Display column type information.
      -c, --comments Preserve comments. Send comments to the server. The
      default is --skip-comments (discard comments), enable
      with --comments
      -C, --compress Use compression in server/client protocol.
      -#, --debug[=#] This is a non-debug version. Catch this and exit
      --debug-check Check memory and open file usage at exit.
      -T, --debug-info Print some debug info at exit.
      -D, --database=name Database to use.
      --default-character-set=name
      Set the default character set.
      --delimiter=name Delimiter to be used.
      -e, --execute=name Execute command and quit. (Disables --force and history
      file)
      -E, --vertical Print the output of a query (rows) vertically.
      -f, --force Continue even if we get an sql error.
      -G, --named-commands
      Enable named commands. Named commands mean this program's
      internal commands; see mysql> help . When enabled, the
      named commands can be used from any line of the query,
      otherwise only from the first line, before an enter.
      Disable with --disable-named-commands. This option is
      disabled by default.
      -g, --no-named-commands
      Named commands are disabled. Use * form only, or use
      named commands only in the beginning of a line ending
      with a semicolon (;) Since version 10.9 the client now
      starts with this option ENABLED by default! Disable with
      '-G'. Long format commands still work from the first
      line. WARNING: option deprecated; use
      --disable-named-commands instead.
      -i, --ignore-spaces Ignore space after function names.

      @

      1 Reply Last reply
      0
      • D Offline
        D Offline
        doforumda
        wrote on 12 Oct 2010, 09:21 last edited by
        #45

        @
        --local-infile Enable/disable LOAD DATA LOCAL INFILE.
        -b, --no-beep Turn off beep on error.
        -h, --host=name Connect to host.
        -H, --html Produce HTML output.
        -X, --xml Produce XML output
        --line-numbers Write line numbers for errors.
        -L, --skip-line-numbers
        Don't write line number for errors. WARNING: -L is
        deprecated, use long version of this option instead.
        -n, --unbuffered Flush buffer after each query.
        --column-names Write column names in results.
        -N, --skip-column-names
        Don't write column names in results. WARNING: -N is
        deprecated, use long version of this options instead.
        -O, --set-variable=name
        Change the value of a variable. Please note that this
        option is deprecated; you can set variables directly with
        --variable-name=value.
        --sigint-ignore Ignore SIGINT (CTRL-C)
        -o, --one-database Only update the default database. This is useful for
        skipping updates to other database in the update log.
        --pager[=name] Pager to use to display results. If you don't supply an
        option the default pager is taken from your ENV variable
        PAGER. Valid pagers are less, more, cat [> filename],
        etc. See interactive help (\h) also. This option does not
        work in batch mode. Disable with --disable-pager. This
        option is disabled by default.
        --no-pager Disable pager and print to stdout. See interactive help
        (\h) also. WARNING: option deprecated; use
        --disable-pager instead.
        -p, --password[=name]
        Password to use when connecting to server. If password is
        not given it's asked from the tty.
        -P, --port=# Port number to use for connection or 0 for default to, in
        order of preference, my.cnf, $MYSQL_TCP_PORT,
        /etc/services, built-in default (3306).
        --prompt=name Set the mysql prompt to this value.
        --protocol=name The protocol of connection (tcp,socket,pipe,memory).
        -q, --quick Don't cache result, print it row by row. This may slow
        down the server if the output is suspended. Doesn't use
        history file.
        -r, --raw Write fields without conversion. Used with --batch.
        --reconnect Reconnect if the connection is lost. Disable with
        --disable-reconnect. This option is enabled by default.
        -s, --silent Be more silent. Print results with a tab as separator,
        each row on new line.
        -S, --socket=name Socket file to use for connection.
        --ssl Enable SSL for connection (automatically enabled with
        other flags). Disable with --skip-ssl.
        --ssl-ca=name CA file in PEM format (check OpenSSL docs, implies
        --ssl).
        --ssl-capath=name CA directory (check OpenSSL docs, implies --ssl).
        --ssl-cert=name X509 cert in PEM format (implies --ssl).
        --ssl-cipher=name SSL cipher to use (implies --ssl).
        --ssl-key=name X509 key in PEM format (implies --ssl).
        --ssl-verify-server-cert
        Verify server's "Common Name" in its cert against
        hostname used when connecting. This option is disabled by
        default.
        -t, --table Output in table format.
        --tee=name Append everything into outfile. See interactive help (\h)
        also. Does not work in batch mode. Disable with
        --disable-tee. This option is disabled by default.
        --no-tee Disable outfile. See interactive help (\h) also. WARNING:
        option deprecated; use --disable-tee instead
        -u, --user=name User for login if not current user.
        -U, --safe-updates Only allow UPDATE and DELETE that uses keys.
        -U, --i-am-a-dummy Synonym for option --safe-updates, -U.
        -v, --verbose Write more. (-v -v -v gives the table output format).
        -V, --version Output version information and exit.
        -w, --wait Wait and retry if connection is down.
        --connect_timeout=# Number of seconds before connection timeout.
        --max_allowed_packet=#
        Max packet length to send to, or receive from server
        --net_buffer_length=#
        Buffer for TCP/IP and socket communication
        --select_limit=# Automatic limit for SELECT when using --safe-updates
        --max_join_size=# Automatic limit for rows in a join when using
        --safe-updates
        --secure-auth Refuse client connecting to server if it uses old
        (pre-4.1.1) protocol
        --server-arg=name Send embedded server this as a parameter.
        --show-warnings Show warnings after every statement.

        Default options are read from the following files in the given order:
        /etc/xampp/my.cnf /opt/lampp/etc/my.cnf ~/.my.cnf
        The following groups are read: mysql client
        The following options may be given as the first argument:
        --print-defaults Print the program argument list and exit
        --no-defaults Don't read default options from any options file
        --defaults-file=# Only read default options from the given file #
        --defaults-extra-file=# Read this file after the global files are read

        @

        1 Reply Last reply
        0
        • D Offline
          D Offline
          doforumda
          wrote on 12 Oct 2010, 09:22 last edited by
          #46

          @
          Variables (--variable-name=value)
          and boolean options {FALSE|TRUE} Value (after reading options)


          auto-rehash FALSE
          character-sets-dir (No default value)
          column-type-info FALSE
          comments FALSE
          compress FALSE
          debug-check FALSE
          debug-info FALSE
          database (No default value)
          default-character-set latin1
          delimiter ;
          vertical FALSE
          force FALSE
          named-commands FALSE
          ignore-spaces FALSE
          local-infile FALSE
          no-beep FALSE
          host (No default value)
          html FALSE
          xml FALSE
          line-numbers TRUE
          unbuffered FALSE
          column-names TRUE
          sigint-ignore FALSE
          port 3306
          prompt mysql>
          quick FALSE
          raw FALSE
          reconnect TRUE
          socket /opt/lampp/var/mysql/mysql.sock
          ssl FALSE
          ssl-ca (No default value)
          ssl-capath (No default value)
          ssl-cert (No default value)
          ssl-cipher (No default value)
          ssl-key (No default value)
          ssl-verify-server-cert FALSE
          table FALSE
          user root
          safe-updates FALSE
          i-am-a-dummy FALSE
          connect_timeout 0
          max_allowed_packet 16777216
          net_buffer_length 16384
          select_limit 1000
          max_join_size 1000000
          secure-auth FALSE
          show-warnings FALSE

          @

          1 Reply Last reply
          0
          • L Offline
            L Offline
            lyuts
            wrote on 12 Oct 2010, 09:26 last edited by
            #47

            Hm, apparently mysql is rather strict in terms of specifying parameters. Try to follow ¤ Dii ¤'s instructions.

            I'm a rebel in the S.D.G.

            1 Reply Last reply
            0
            • D Offline
              D Offline
              doforumda
              wrote on 12 Oct 2010, 09:30 last edited by
              #48

              whats Dii and where are these instructions?

              1 Reply Last reply
              0
              • L Offline
                L Offline
                lyuts
                wrote on 12 Oct 2010, 09:30 last edited by
                #49

                Here is his post.

                [quote author="¤ Dii ¤" date="1286874970"]Do it this way, then it will prompt for a password:

                @/opt/lampp/bin/mysql -D testTwo -h localhost -u root -p
                @
                [/quote]

                I'm a rebel in the S.D.G.

                1 Reply Last reply
                0
                • D Offline
                  D Offline
                  Dii
                  wrote on 12 Oct 2010, 09:31 last edited by
                  #50

                  lol, don't be write only :)

                  /opt/lampp/bin/mysql -D testTwo -h localhost -u root -p

                  1 Reply Last reply
                  0
                  • D Offline
                    D Offline
                    Dii
                    wrote on 12 Oct 2010, 09:32 last edited by
                    #51

                    BTW if you do this, AND it's working, you end up in mysql command line interface, you can get out with 'exit'

                    1 Reply Last reply
                    0
                    • D Offline
                      D Offline
                      doforumda
                      wrote on 12 Oct 2010, 09:32 last edited by
                      #52

                      sorry i couldnt notice Dii user

                      1 Reply Last reply
                      0
                      • L Offline
                        L Offline
                        lyuts
                        wrote on 12 Oct 2010, 09:33 last edited by
                        #53

                        Wow, mysql is full of surprises. Never got those with psql. ¤ Dii ¤, does it have \q command?

                        I'm a rebel in the S.D.G.

                        1 Reply Last reply
                        0
                        • D Offline
                          D Offline
                          doforumda
                          wrote on 12 Oct 2010, 09:34 last edited by
                          #54

                          yes i get into mysql command line

                          1 Reply Last reply
                          0
                          • D Offline
                            D Offline
                            doforumda
                            wrote on 12 Oct 2010, 09:35 last edited by
                            #55

                            whats the reason that my database is not opening in qt?

                            1 Reply Last reply
                            0
                            • D Offline
                              D Offline
                              Dii
                              wrote on 12 Oct 2010, 09:38 last edited by
                              #56

                              lyuts: yes \q is working too

                              doforumda: ok, so get into the mysql comand line with the command above

                              /opt/lampp/bin/mysql -D testTwo -h localhost -u root -p

                              and then do this:

                              grant all on testTwo.* to 'root'@'localhost' ;

                              Then we have a working mysql, and the rights are granted, we can get back to your Qt program.

                              1 Reply Last reply
                              0
                              • L Offline
                                L Offline
                                lyuts
                                wrote on 12 Oct 2010, 09:41 last edited by
                                #57

                                I hope the next post will be like "Hooray, I got it working!!!" :)

                                I'm a rebel in the S.D.G.

                                1 Reply Last reply
                                0
                                • D Offline
                                  D Offline
                                  doforumda
                                  wrote on 12 Oct 2010, 09:42 last edited by
                                  #58

                                  there is an error in sql syntax
                                  @
                                  mysql> grant all on testTwo.* to ‘root’@’localhost’;
                                  ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '��root’@’localhost’' at line 1
                                  @

                                  1 Reply Last reply
                                  0
                                  • D Offline
                                    D Offline
                                    Dii
                                    wrote on 12 Oct 2010, 09:46 last edited by
                                    #59

                                    Ok, back to your Qt program:

                                    @#include <QApplication>
                                    #include <QtSql>

                                    int main(int argc, char *argv[])
                                    {
                                    QCoreApplication a(argc, argv);

                                    QSqlDatabase db = QSqlDatabase::addDatabase("QMYSQL");
                                    db.setDatabaseName("testTwo");
                                    db.setUserName("root");
                                    db.setPassword("");
                                    db.setHostName("localhost");
                                    
                                    bool ok = db.open();
                                    qDebug() << ok;
                                    
                                    QSqlQuery query;
                                    query.exec&#40;"SELECT firstname,lastname FROM testTable"&#41;;
                                    while(query.next()) {
                                        QString firstName = query.value(0).toString();
                                        QString secondName = query.value(1).toString();
                                        qDebug() << "First Name: " << firstName << "Last Name:" << secondName;
                                        qDebug() << db.lastError();
                                    }
                                    return 0;
                                    

                                    }@

                                    Notice, we don't set a password here.
                                    The end is 'return 0' instead of 'a.exec()', and it won't hang. The exec() starts the main event loop, and you don't use it here...

                                    1 Reply Last reply
                                    0
                                    • L Offline
                                      L Offline
                                      lyuts
                                      wrote on 12 Oct 2010, 09:46 last edited by
                                      #60

                                      I think you need to check apostrophes in that command.

                                      I'm a rebel in the S.D.G.

                                      1 Reply Last reply
                                      0
                                      • D Offline
                                        D Offline
                                        Dii
                                        wrote on 12 Oct 2010, 09:46 last edited by
                                        #61

                                        ok, you have wrong apostrof type there. I mean this >> '

                                        1 Reply Last reply
                                        0
                                        • D Offline
                                          D Offline
                                          doforumda
                                          wrote on 12 Oct 2010, 09:48 last edited by
                                          #62

                                          i tried without apostrophes as well but same error

                                          1 Reply Last reply
                                          0

                                          52/150

                                          12 Oct 2010, 09:32

                                          • Login

                                          • Login or register to search.
                                          52 out of 150
                                          • First post
                                            52/150
                                            Last post
                                          0
                                          • Categories
                                          • Recent
                                          • Tags
                                          • Popular
                                          • Users
                                          • Groups
                                          • Search
                                          • Get Qt Extensions
                                          • Unsolved