Search Results

Search found 30606 results on 1225 pages for 'database relations'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 309/1225 | < Previous Page | 305 306 307 308 309 310 311 312 313 314 315 316  | Next Page >

  • When using a HiLo ID generation strategy, what types should be used to hold Ids?

    - by UpTheCreek
    I'm asking this from a c#/NHibnernate perspective, but it's generally applicable. The concern is that the HiLo strategy goes though id's pretty quickly, and for example a low record-count table (Such as Users) is sharing from the same set of id's as a high record-count table (Such as comments). So you can potentially get to high numbers quicker that with other strategies. So what do people recommend? Code side: int/uint/long/ulong? DBSide: int/bigint? My feeling is to go with longs and bigingts, but would like a sanity check :)

    Read the article

  • Data scheme question

    - by Matt
    I am designing a data model for a local city page, more like requirements for it. So 4 tables: Country, State, City, neighbourhood. Real life relationships is: Country owns multiple State which owns multiple cities which ows multiple neighbourhoods. In the data model: Do we link these with FK the same way or link each with each? Like in each table there will even be a Country ID, State ID, CityID and NeighbourhoodID so each connected with each? Other wise to reach neighbourhood from country we need to join 2 other tables in between? There are more tables I need to maintain for IP addess of cities, latitude/longitude, etc.

    Read the article

  • Can I do transactions and locks in CouchDB?

    - by damian
    I need to do transactions (begin, commit or rollback), locks (select for update). How can I do it in a document model db? Edit: The case is this: I want to run an auctions site. And I think how to direct purchase as well. In a direct purchase I have to decrement the quantity field in the item record, but only if the quantity is greater than zero. That is why I need locks and transactions. I don't know how to address that without locks and/or transactions. Can I solve this with CouchDB?

    Read the article

  • VB6. DataEnvironment: How to Configure/Set Trusted Connection?

    - by Mblua
    Hi, I have a DataEnvironment component in my VB 6 application. I cant configure the DataEnvironment connection to use trusted connection without ask me how to connect. I could set prompt to never appear, but it doesnt connect becouse it doesnt use trusted. In this link you could see the screens of DataEnvironment Connection Options and the prompt. Google Presentation Link I need this program to be executed from a D.O.S console without prompt anything. Thanks a lot!

    Read the article

  • Fluent nHibernate - How to map a non-key column on an association table?

    - by The Matt
    Taking an example that is provided on the Fluent nHibernate website, I need to extend it slightly: I need to add a 'Quantity' column to the StoreProduct table. How would I map this using nHibernate? An example mapping is provided for the given scenario above, but I'm not sure how I would get the Quantity column to map: public class StoreMap : ClassMap<Store> { public StoreMap() { Id(x => x.Id); Map(x => x.Name); HasMany(x => x.Employee) .Inverse() .Cascade.All(); HasManyToMany(x => x.Products) .Cascade.All() .Table("StoreProduct"); } }

    Read the article

  • im unable to validate a login of users ,since if im entering the wrong values my datareader is not getting executed y ?

    - by Salman_Khan
    //code private void glassButton1_Click(object sender, EventArgs e) { if (textBox1.Text == "" || textBox1.Text == "" || comboBox1.SelectedIndex == 0) { Message m = new Message(); m.ShowDialog(); } else { try { con.ConnectionString = "Data source=BLACK-PEARL;Initial Catalog=LIFELINE ;User id =sa; password=143"; con.Open(); SqlCommand cmd = new SqlCommand("Select LoginID,Password,Department from Login where LoginID=@loginID and Password=@Password and Department=@Department", con); cmd.Parameters.Add(new SqlParameter("@loginID", textBox1.Text)); cmd.Parameters.Add(new SqlParameter("@Password", textBox2.Text)); cmd.Parameters.Add(new SqlParameter("@Department", comboBox1.Text)); SqlDataReader dr = cmd.ExecuteReader(); if (dr.Read()) { string Strname = dr[0].ToString(); string StrPass = dr[1].ToString(); string StrDept = dr[2].ToString(); if(dr[2].ToString().Equals(comboBox1.Text)&&dr[0].ToString().Equals(textBox1.Text)&&dr[1].ToString().Equals(textBox2.Text)) { MessageBox.Show("Welcome"); } else { MessageBox.Show("Please Enter correct details"); } } dr.Close(); } catch (Exception ex) { MessageBox.Show("Exception" + ex); } finally { con.Close(); } } }

    Read the article

  • T-SQL MERGE - finding out which action it took

    - by IanC
    I need to know if a MERGE statement performed an INSERT. In my scenario, the insert is either 0 or 1 rows. Test code: DECLARE @t table (C1 int, C2 int) DECLARE @C1 INT, @C2 INT set @c1 = 1 set @c2 = 1 MERGE @t as tgt USING (SELECT @C1, @C2) AS src (C1, C2) ON (tgt.C1 = src.C1) WHEN MATCHED AND tgt.C2 != src.C2 THEN UPDATE SET tgt.C2 = src.C2 WHEN NOT MATCHED BY TARGET THEN INSERT VALUES (src.C1, src. C2) OUTPUT deleted.*, $action, inserted.*; SELECT inserted.* The last line doesn't compile (no scope, unlike a trigger). I can't get access to @action, or the output. Actually, I don't want any output meta data. How can I do this?

    Read the article

  • mysql filtering result using left outer join

    - by user288178
    my query: SELECT content.*, activity_log.content_id FROM content LEFT JOIN activity_log ON content.id = activity_log.content_id AND sess_id = '$sess_id' WHERE activity_log.content_id IS NULL AND visibility = $visibility AND content.reported < ".REPORTED_LIMIT." AND content.file_ready = 1 LIMIT 1 The purpose of that query is to get 1 row from the content table that has not been viewed by the user (identified by session_id), but it still returns contents that have been viewed. What is wrong? ( I have checked the table making sure that the content_ids are there) Note: I think this is more efficient than using subqueries, thoughts?

    Read the article

  • Exceptions in ASP.MVC

    - by George
    Hello guys, I'm here again with another question about MVC. Here is the deal. I have a simple table/class with an Id and a Name. Names suppossed to be unique, and are modeled like that in the DB. I created my controller and everything just works fine. But if I try to insert a name that already exists, an exception should be thrown. I'm just not finding what is the correct kind of exception and it's namespace. The error must be coming from the DB, so... Any ideas? Thanks

    Read the article

  • Django: Serializing models in a nested data structure?

    - by Rosarch
    It's easy to serialize models in an iterable: def _toJSON(models): return serializers.serialize("json", models, ensure_ascii=False) What about when I have something more complicated: [ (Model_A_1, [Model_B_1, Model_B_2, Model_B_3]), (Model_A_2, [Model_B_3, Model_B_4, Model_B_5, Model_B_59]), (Model_A_3, [Model_B_6, Model_B_7]), ] I tried serializing each model as it was added to the structure, then serializing the whole thing with simplejson.dumps, but that causes the JSON defining each model to be escaped. Is there a better way to do this?

    Read the article

  • SQL Server Concatenate string column value to 5 char long

    - by mrp
    Scenario: I have a table1(col1 char(5)); A value in table1 may '001' or '01' or '1'. Requirement: Whatever value in col1, I need to retrive it in 5 char length concatenate with leading '0' to make it 5 char long. Technique I applied: select right(('00000' + col1),5) from table1; I didn't see any reason, why it doesn't work? but it didn't. Can anyone help me, how I can achieve the desired result?

    Read the article

  • What is the most efficient procedure for implementing a sortable ajax list on the backend?

    - by HenryL
    The most common method is to assign a sequential order field for each item in the list and do an update that maintains the sequence with every ajax sort operation. Unfortunately, this requires an update to each item of the list every time someone sorts. This is fine for small lists, but what's the best way to implement sorting for larger lists that are constantly updated? I am looking for something that minimizes DB IO.

    Read the article

  • Python: mysqldb install error

    - by Grenko
    So i've been pulling my hair out trying to install the mysqldb package. When i run the build i get a long transcript of errors, heres just part of it, i would posit it all but its huge list of errors [rv@med240-183 MySQL-python-1.2.3c1]$ sudo python setup.py build [sudo] password for rv: running build running build_py copying MySQLdb/release.py -> build/lib.linux-i686-2.6/MySQLdb running build_ext building '_mysql' extension gcc -pthread -fno-strict-aliasing -DNDEBUG -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m32 -march=i586 -mtune=generic -fasynchronous-unwind-tables -D_GNU_SOURCE -fPIC -fPIC -Dversion_info=(1,2,3,'gamma',1) -D__version__=1.2.3c1 -I/usr/include/mysql -I/usr/include/python2.6 -c _mysql.c -o build/temp.linux-i686-2.6/_mysql.o -g -pipe -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m32 -fasynchronous-unwind-tables -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -fno-strict-aliasing -fwrapv -fPIC -DUNIV_LINUX _mysql.c:36:23: error: my_config.h: No such file or directory _mysql.c:38:19: error: mysql.h: No such file or directory Any ideas?

    Read the article

  • SQLite - ON DUPLICATE KEY UPDATE

    - by Alix Axel
    MySQL has something like this: INSERT INTO visits (ip, hits) VALUES ('127.0.0.1', 1) ON DUPLICATE KEY UPDATE hits = hits + 1; As far as I'm know this feature doesn't exist in SQLite, what I want to know is if there is any way to archive the same effect without having to execute two queries. Also, if this is not possible, what do you prefer: SELECT + (INSERT or UPDATE) or UPDATE (+ INSERT if UPDATE fails)

    Read the article

  • SQLServer using too much memory

    - by Israel Pereira Valverde
    I have installed on my desktop machine (with windows 7) SQLServer 2008 R2 Express. I have only one local server running (./SQLEXPRESS) but the sqlserver process is taking ALL the RAM possible. With an machine with 3GB of RAM the things starts to get slow, so I limited the maximun amount of RAM in the server, and now, constantly the SQLServer give some error messages that the memory is not enought. It's using 1GB of RAM with only one LOCAL server with 2 databases completely empty, how 1GB of RAM isn't enought ? When the process start it's using an really acceptable amount of memory (around 80MB) but it's keep increasing until it reaches the maximun defined and start to complain about having not enought memory available. In that point I have to restart the server to use it again. I have read about an hotfix to solve one of the errors I got from sqlserver: There is insufficient system memory in resource pool 'internal' to run this query But it's already installed on my sqlserver. Why it's using so much memory?

    Read the article

  • Datamapper Clone Record w/ New ID

    - by BouncePast
    class Item include DataMapper::Resource property :id, Serial property :title, String end item = Item.new(:title = 'Title 1') # :id = 1 item_clone = Item.first(:id = 1).clone item_clone.save This does "clone" the object as described but how can this be done so it applies a different ID once the record is saved, e.g. #

    Read the article

  • django related_name for field clashes.

    - by Absolute0
    I am getting a field clash in my models: class Visit(models.Model): user = models.ForeignKey(User) visitor = models.ForeignKey(User) Error: One or more models did not validate: profiles.visit: Accessor for field 'user' clashes with related field 'User.visit_set'. Add a related_name argument to the definition for 'user'. profiles.visit: Accessor for field 'visitor' clashes with related field 'User.visit_set'. Add a related_name argument to the definition for 'visitor'. what would be a sensible 'related_field' to use on visitor field? This model basically represents the visits that take place to a particular user's profile. Also should I replace any of the ForeignKey's with a ManyToManyField? The logic is a bit confusing. Edit: This seems to fix it, but I am unsure if its what I want. :) class Visit(models.Model): user = models.ForeignKey(User) visitor = models.ForeignKey(User, related_name='visitors')

    Read the article

  • Django User "per project" group assignation

    - by Ben G
    Hi, Here's my problem : my site has users, which can create projects, and access other user's projects. Each project can assign different rights to users. So, i could have Project A : user "John" is in group "manager" , and Project "B" user "John" is in group "worker". How could I use the Django User authentication model to do that ? From a SQL point a view, what i would like is to be able to add "project_id" in the primary key for the "auth_user_groups" table. I don't think profile is of any help here. Any advice ? UPDATE : "worker" and "manager" are just two examples of the permission group (or "roles") that my application defines. There will be more in the future. Eg : i will probably also have "admin", "reporting", etc...

    Read the article

  • Date range intersection in SQL

    - by Will
    I have a table where each row has a start and stop date-time. These can be arbitrarily short or long spans. I want to query the sum duration of the intersection of all rows with two start and stop date-times. How can you do this in MySQL? Or do you have to select the rows that intersect the query start and stop times, then calculate the actual overlap of each row and sum it client-side?

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 305 306 307 308 309 310 311 312 313 314 315 316  | Next Page >