Search Results

Search found 5153 results on 207 pages for 'unique ptr'.

Page 94/207 | < Previous Page | 90 91 92 93 94 95 96 97 98 99 100 101  | Next Page >

  • What's the best way to use NHibernate for objects without ID?

    - by Khash
    I have some classes in my app that don't require an ID to be persisted. These could be things like user logs or audit records. I can add an arbitaty id to them but I would like to avoid that as they don't mean anything. The retrieval of these objects is always on another key (like UserId) which is not unique to the record.

    Read the article

  • Sorting string column containing numbers in SQL?

    - by Ish
    Dear Folks, I am trying to sort string column (containing numbers). // SELECT `name` FROM `mytable` ORDER BY `name` ASC +----------+ +-- name --+ +----------+ +-- a 1 ---+ +-- a 12 --+ +-- a 2 ---+ +-- a 3 ---+ You see natural sorting algorithm of Mysql is placing a 12 after a 1 (which is ok for most apps), But I have unique needs, so I want result should be sorted like this. +----------+ +-- name --+ +----------+ +-- a 1 ---+ +-- a 2 ---+ +-- a 3 ---+ +-- a 12 --+ Is it possible with just SQL, or I have to manipulate result-set at application level? Thanks for reading...

    Read the article

  • Circular database relationships. Good, Bad, Exceptions?

    - by jim
    I have been putting off developing this part of my app for sometime purely because I want to do this in a circular way but get the feeling its a bad idea from what I remember my lecturers telling me back in school. I have a design for an order system, ignoring the everything that doesn't pertain to this example I'm left with: CreditCard Customer Order I want it so that, Customers can have credit cards (0-n) Customers have orders (1-n) Orders have one customer(1-1) Orders have one credit card(1-1) Credit cards can have one customer(1-1) (unique ids so we can ignore uniqueness of cc number, husband/wife may share cc instances ect) Basically the last part is where the issue shows up, sometimes credit cards are declined and they wish to use a different one, this needs to update which their 'current' card is but this can only change the current card used for that order, not the other orders the customer may have on disk. Effectively this creates a circular design between the three tables. Possible solutions: Either Create the circular design, give references: cc ref to order, customer ref to cc customer ref to order or customer ref to cc customer ref to order create new table that references all three table ids and put unique on the order so that only one cc may be current to that order at any time Essentially both model the same design but translate differently, I am liking the latter option best at this point in time because it seems less circular and more central. (If that even makes sense) My questions are, What if any are the pros and cons of each? What is the pitfalls of circular relationships/dependancies? Is this a valid exception to the rule? Is there any reason I should pick the former over the latter? Thanks and let me know if there is anything you need clarified/explained. --Update/Edit-- I have noticed an error in the requirements I stated. Basically dropped the ball when trying to simplify things for SO. There is another table there for Payments which adds another layer. The catch, Orders can have multiple payments, with the possibility of using different credit cards. (if you really want to know even other forms of payment). Stating this here because I think the underlying issue is still the same and this only really adds another layer of complexity.

    Read the article

  • codeIgniter: pass parameter to a select query from previous query

    - by krike
    I'm creating a little management tool for the browser game travian. So I select all the villages from the database and I want to display some content that's unique to each of the villages. But in order to query for those unique details I need to pass the id of the village. How should I do this? this is my code (controller): function members_area() { global $site_title; $this->load->model('membership_model'); if($this->membership_model->get_villages()) { $data['rows'] = $this->membership_model->get_villages(); $id = 1;//this should be dynamic, but how? if($this->membership_model->get_tasks($id)): $data['tasks'] = $this->membership_model->get_tasks($id); endif; } $data['title'] = $site_title." | Your account"; $data['main_content'] = 'account'; $this->load->view('template', $data); } and this is the 2 functions I'm using in the model: function get_villages() { $q = $this->db->get('villages'); if($q->num_rows() > 0) { foreach ($q->result() as $row) { $data[] = $row; } return $data; } } function get_tasks($id) { $this->db->select('name'); $this->db->from('tasks'); $this->db->where('villageid', $id); $q = $this->db->get(); if($q->num_rows() > 0) { foreach ($q->result() as $task) { $data[] = $task; } return $data; } } and of course the view: <?php foreach($rows as $r) : ?> <div class="village"> <h3><?php echo $r->name; ?></h3> <ul> <?php foreach($tasks as $task): ?> <li><?php echo $task->name; ?></li> <?php endforeach; ?> </ul> <?php echo anchor('site/add_village/'.$r->id.'', '+ add new task'); ?> </div> <?php endforeach; ?> ps: please do not remove the comment in the first block of code!

    Read the article

  • How to Auto-Increment Non-Primary Key? - SQL Server

    - by user311509
    CREATE TABLE SupplierQuote ( supplierQuoteID int identity (3504,2) CONSTRAINT supquoteid_pk PRIMARY KEY, PONumber int identity (9553,20) NOT NULL . . . CONSTRAINT ponumber_uq UNIQUE(PONumber) ); The above ddl produces an error: Msg 2744, Level 16, State 2, Line 1 Multiple identity columns specified for table 'SupplierQuote'. Only one identity column per table is allowed. How can i solve it? I want PONumber to be auto-incremented.

    Read the article

  • Updating value in Linq to SQL IEnumerable

    - by Learner
    Using Linq to SQL: if(!parentlist.childlist.Contains(row1)) parentlist.childlist.Add(row1); else How do I update the required childlist row with row1? Each row of the child list has a unique id. parentlist implements IEnumerable and childlist is IList.

    Read the article

  • Can I raise System Error in sql Server in a stored procedure.

    - by Shantanu Gupta
    I am writing a stored procedure where i m using try catch block. Now i have a unique column in a table. When i try to insert duplicate value it throws exception with exception no 2627. I want this to be done like this if (exists(select * from tblABC where col1='value')=true) raiseError(2627)--raise system error that would have thrown if i would have used insert query to insert duplicate value And which method will be better, using insert query or checking for duplicate value before insertion using Select query ?

    Read the article

  • Assigning IDs to instances of a class (Pythonic)

    - by mellort
    I want to have each instance of some class have a unique integer identifier based on the order that I create them, starting with (say) 0. In Java, I could do this with a static class variable. I know I can emulate the same sort of behavior with Python, but what would be the most 'Pythonic' way to do this? Thanks

    Read the article

  • advance/basic and smartphone views in Rails

    - by aleds
    In a new Rail app I have to consider 2 differents user's type: basic and Advanced and I have to create smartphone views( unique view for both user's type). Then I have 3 view/layout: - web advance - web basic - smartphone I already have the adv/basic flag for the user, and I followed the RBates tutorial http://asciicasts.com/episodes/199-mobile-devices. What is the best way to manage the 3 views/layout ?

    Read the article

  • hibernate modeling relationships managed through an intermediate table

    - by shikarishambu
    I have a datamodel that has an intermediate table to manage relationships between entities. For example, tables Person and Organization are related through the Relationship table Party (table) - ID Person (table) - ID (references Party.ID) - name Organization (table) -ID (references Party.ID) -name Relationship (table) -ID (PK) -type (references relationshiptype lookup) -fromID (references Party.ID) -ToID (references Party.ID) -fromDate -ToDate Type+fromID+ToID+fromDate+ToDate is guaranteed to be unique. How do I manage this using hibernate? TIA

    Read the article

  • How to write my own global lock / unlock functions for PostgreSQL

    - by rafalmag
    I have postgresql (in perlu) function getTravelTime(integer, timestamp), which tries to select data for specified ID and timestamp. If there are no data or if data is old, it downloads them from external server (downloading time ~300ms). Multiple process use this database and this function. There is an error when two process do not find data and download them and try to do an insert to travel_time table (id and timestamp pair have to be unique). I thought about locks. Locking whole table would block all processes and allow only one to proceed. I need to lock only on id and timestamp. pg_advisory_lock seems to lock only in "current session". But my processes uses their own sessions. I tried to write my own lock/unlock functions. Am I doing it right? I use active waiting, how can I omit this? Maybe there is a way to use pg_advisory_lock() as global lock? My code: CREATE TABLE travel_time_locks ( id_key integer NOT NULL, time_key timestamp without time zone NOT NULL, UNIQUE (id_key, time_key) ); ------------ -- Function: mylock(integer, timestamp) DROP FUNCTION IF EXISTS mylock(integer, timestamp) CASCADE; -- Usage: SELECT mylock(1, '2010-03-28T19:45'); -- function tries to do a global lock similar to pg_advisory_lock(key, key) CREATE OR REPLACE FUNCTION mylock(id_input integer, time_input timestamp) RETURNS void AS $BODY$ DECLARE rows int; BEGIN LOOP BEGIN -- active waiting here !!!! :( INSERT INTO travel_time_locks (id_key, time_key) VALUES (id_input, time_input); EXCEPTION WHEN unique_violation THEN CONTINUE; END; EXIT; END LOOP; END; $BODY$ LANGUAGE 'plpgsql' VOLATILE COST 1; ------------ -- Function: myunlock(integer, timestamp) DROP FUNCTION IF EXISTS myunlock(integer, timestamp) CASCADE; -- Usage: SELECT myunlock(1, '2010-03-28T19:45'); -- function tries to do a global unlock similar to pg_advisory_unlock(key, key) CREATE OR REPLACE FUNCTION myunlock(id_input integer, time_input timestamp) RETURNS integer AS $BODY$ DECLARE BEGIN DELETE FROM ONLY travel_time_locks WHERE id_key=id_input AND time_key=time_input; RETURN 1; END; $BODY$ LANGUAGE 'plpgsql' VOLATILE COST 1;

    Read the article

  • Why One-to-one relationship dosen't work?

    - by eugenn
    I'm trying to create a very simple relationship between two objects. Can anybody explain me why I can't find the Company object via findBy method? class Company { String name String desc City city static constraints = { city(unique: true) } } class City { String name static constraints = { } } class BootStrap { def init = { servletContext -> new City(name: 'Tokyo').save() new City(name: 'New York').save() new Company(name: 'company', city: City.findByName('New York')).save() def c = Company.findByName('company') // Why c=null????! } def destroy = { } }

    Read the article

  • Better alternative to autonumber primary keys

    - by Comrad_Durandal
    I am looking for a better primary key than the autonumber data type, namely for the reason that it's limited to a long integer, when I really just need the field to reflect a number or text string that will never ever repeat, no matter HOW many records are added or deleted from the table. The problem is I am not sure how to implement something like turning the current date and time into a hexadecimal string and using that as a unique field I can use as a primary key. Am I just being too paranoid about running out of space?

    Read the article

  • Is there a way to find a specific file and then change into the directory containing it in one go?

    - by bergyman
    I'm looking for a way to find what I know will be a unique file, and then change into the directory containing that file. Something along the lines of: find . -name 'Subscription.java' | xargs cd Or: find . -name 'Subscription.java' -exec cd {} \; I know this won't work because it's both trying to cd supplying the entire absolute path, which contains the file, and also because xargs can't do any built in shell commands...but you get the point of what I want to accomplish.

    Read the article

  • Grails' GORM constraint question

    - by xain
    Hi, I have the following Domain Class: class Metric { String name float value static belongsTo = [Person,Corporation] static indexes = { name() } } How can I add a constraint so Person,Corporation and name are unique ? Thanks.

    Read the article

  • MySQL not using index on DATE when used with '<' or '>' operators?

    - by Haroldo
    I'm using explain to test these queries. The col type is DATE this uses index: explain SELECT events.* FROM events WHERE events.date = '2010-06-11' this doesnt explain SELECT events.* FROM events WHERE events.date >= '2010-06-11' index as follows (phpmyadmin) Action Keyname Type Unique Packed Field Cardinality Collation Null Comment Edit Drop PRIMARY BTREE Yes No event_id 18 A Edit Drop date BTREE No No date 0 A i notice cardinality is 0, though there are some rows with the same date..

    Read the article

  • How should a Gnome applet store its configuration data?

    - by George Edison
    I have a Gnome applet written in Python. In order to save configuration data/settings, it creates a file ~/.appname. However, this prevents multiple instances of the applet from being added to the panel because each cannot have its own settings. How can I store the settings in a way that allows each instance to have its own unique settings? Update: I specifically want to know how to store settings per instance.

    Read the article

  • sqlite, UPDATE OR REPLACE

    - by acidzombie24
    I do something like UPDATE OR REPLACE someTable SET a=1, b=2 WHERE c=3 I expect if it doesnt exist it will be inserted into the DBs. But nothing happens and i get no errors. How can i insert data, replace it if it already exist and use a where for the condition (instead of replacing BC of a unique ID)

    Read the article

< Previous Page | 90 91 92 93 94 95 96 97 98 99 100 101  | Next Page >