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  • SQL Server Constraints Across Tables

    - by chama
    I have a SQL Server database with an Apartment table (which has columns FloorNum and BuildingID) and an ApartmentBuilding table (with column NumFloors). Is there any way to set up a constraint (using the SQL Server UI) to check that Apartment.FloorNum is greater than ApartmentBuilding.NumFloors? I tried this: FloorNum > ApartmentBuilding.NumFloors but now I realize that I somehow have to join the columns on the BuildingID, but I have no idea how to do that within a constraint. Thanks for your help!

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  • Querying Two Tables At Once

    - by John
    Hello, I am trying to do what I believe is called a join query. First, in a MySQL table called "login," I want to look up what "loginid" is in the record where "username" equals $profile. (This will be just one record / row in the MySQL table). Then, I want to take that "loginid" and look up all rows / records in a different MySQL table called "submission," and pull data that have that "loginid." This could possibly be more than one record / row. How do I do this? The code below doesn't seem to work. Thanks in advance, John $profile = mysql_real_escape_string($_GET['profile']); $sqlStr = "SELECT l.username, l.loginid, s.loginid, s.submissionid, s.title, s.url, s.datesubmitted, s.displayurl FROM submission AS s, login AS l WHERE l.username = '$profile', s.loginid = l.loginid ORDER BY s.datesubmitted DESC";

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  • Oracle DBMS_PROFILER only shows Anonymous in the results tables

    - by Greg Reynolds
    I am new to DBMS_PROFILER. All the examples I have seen use a simple top-level procedure to demonstrate the use of the profiler, and from there get all the line numbers etc. I deploy all code in packages, and I am having great difficulty getting my profile session to populate the plsql_profiler_units with useful data. Most of my runs look like this: RUNID RUN_COMMENT UNIT_OWNER UNIT_NAME SECS PERCEN ----- ----------- ----------- -------------- ------- ------ 5 Test <anonymous> <anonymous> .00 2.1 Profiler 5 Test <anonymous> <anonymous> .00 2.1 Profiler 5 Test <anonymous> <anonymous> .00 2.1 Profiler I have just embedded the calls to the dbms_profiler.start_profiler, flush_data and stop_profiler as per all the examples. The main difference is that my code is in a package, and calls in to other package. Do you have to profile every single stored procedure in your call stack? If so that makes this tool a little useless! I have checked http://www.dba-oracle.com/t_plsql_dbms_profiler.htm for hints, among other similar sites.

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  • Decentralized synchronized secure data storage

    - by Alberich
    Introduction Hi, I am going to ask a question which seems utopic for me, but I need to know if there is a way to achieve what I need. And if not, I need to know why not. The idea Suppose I have a database structure, in MySql. I want to create some solution to allow anyone (no matter who, no matter where) to have a synchronized copy (updated clone) of this database (with its content) Well, and it is not going to be just one synchronized copy, it could (and should) be a multiple replication (supposing the basic, this means, for example, ten copies all over the world) And, the most important thing: It must be secure. By secure I mean only real-accepted transactions will be synchronized with all the others (no matter how many) database copies/clones. Note: Since it would be quite difficult to make the synchronization in real-time, I will design everything to make this feature dispensable. So it is not required. My auto-suggestion This is how I am thinking to manage it: Time identifiers and Updates checking: Every action (insert, update, delete...) will be stored as the action instruction itself, associated to the time identifier. [I think better than a DATETIME field, it'll be an INT one, with the number of miliseconds passed from 1st january 2013 on, for example]. So each copy is going to ask to the "neighbour copy" for new actions done since last update, and execute them after checking they are allowed. Problem 1: the "neighbour copy" could be outdated too. Solution 1: do not ask just one neighbour, create a random list with some of the copies/clones and ask them for news (I could avoid the list and ask ALL the clones for updates, but this will be inefficient if clones number ascends too much). Problem 2: Real-time global synchronization is not active. What if... Someone at CLONE_ENTERPRISING inserts a row into TABLE. ... this row goes to every clone ... Someone at CLONE_FIXEMALL deletes this row. ... and at the same time, somewhere in an outdated clone ... Someone at CLONE_DROPOUT edits this row (now inexistent at the other clones) Solution 2: easy stuff, force a GLOBAL synchronization before doing any new "depending-on-third-data action" (edit, for example). This global synch. will be unnecessary when making an INSERT, for instance. Note: Well, someone could have some fun, and make the same insert in two clones... since they're not getting updated in real-time, this row will exist twice. But, it's the same as when we have one single database, in some needed cases we check if there is an existing same-row before doing the final action. Not a problem. Problem 3: It is possible to edit the code and do not filter actions, so someone could spread instructions to delete everything, or just make some trolling activity. This is not a problem, since good clones will always be somewhere. Those who got bad won't interest anymore. I really appreciate if you read. I know this is not the perfect solution, it has possibly hundred of holes, but it is my basic start. I will now appreciate anything you can teach me now. Thanks a lot. PS.: It could be that all this I am trying already exists and has its own name. Sorry for asking then (I'd anyway thank this name, if it exists)

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  • Fluent Nhibernate - how do i specify table schemas when auto generating tables in SQL CE 4

    - by daffers
    I am using SQL CE as a database for running local and CI integration tests (normally our site runs on normal SQL server). We are using Fluent Nhibernate for our mapping and having it create our schema from our Mapclasses. There are only two classes with a one to many relationship between them. In our real database we use a non dbo schema. The code would not work with this real database at first until i added schema names to the Table() methods. However doing this broke the unit tests with the error... System.Data.SqlServerCe.SqlCeException : There was an error parsing the query. [ Token line number = 1,Token line offset = 26,Token in error = User ] These are the classes and associatad MapClasses (simplified of course) public class AffiliateApplicationRecord { public virtual int Id { get; private set; } public virtual string CompanyName { get; set; } public virtual UserRecord KeyContact { get; private set; } public AffiliateApplicationRecord() { DateReceived = DateTime.Now; } public virtual void AddKeyContact(UserRecord keyContactUser) { keyContactUser.Affilates.Add(this); KeyContact = keyContactUser; } } public class AffiliateApplicationRecordMap : ClassMap<AffiliateApplicationRecord> { public AffiliateApplicationRecordMap() { Schema("myschema"); Table("Partner"); Id(x => x.Id).GeneratedBy.Identity(); Map(x => x.CompanyName, "Name"); References(x => x.KeyContact) .Cascade.All() .LazyLoad(Laziness.False) .Column("UserID"); } } public class UserRecord { public UserRecord() { Affilates = new List<AffiliateApplicationRecord>(); } public virtual int Id { get; private set; } public virtual string Forename { get; set; } public virtual IList<AffiliateApplicationRecord> Affilates { get; set; } } public class UserRecordMap : ClassMap<UserRecord> { public UserRecordMap() { Schema("myschema"); Table("[User]");//Square brackets required as user is a reserved word Id(x => x.Id).GeneratedBy.Identity(); Map(x => x.Forename); HasMany(x => x.Affilates); } } And here is the fluent configuraton i am using .... public static ISessionFactory CreateSessionFactory() { return Fluently.Configure() .Database( MsSqlCeConfiguration.Standard .Dialect<MsSqlCe40Dialect>() .ConnectionString(ConnectionString) .DefaultSchema("myschema")) .Mappings(m => m.FluentMappings.AddFromAssembly(typeof(AffiliateApplicationRecord).Assembly)) .ExposeConfiguration(config => new SchemaExport(config).Create(false, true)) .ExposeConfiguration(x => x.SetProperty("connection.release_mode", "on_close")) //This is included to deal with a SQLCE issue http://stackoverflow.com/questions/2361730/assertionfailure-null-identifier-fluentnh-sqlserverce .BuildSessionFactory(); } The documentation on this aspect of fluent is pretty weak so any help would be appreciated

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  • Visual Studio 2010 "Not enough storage is available to process this command"

    - by Daniel Perez
    I'm fighting with VS 2010 and this error that seems to be very common in previous versions, but it looks like not everyone is having it in the latest version. I've got VS 2010 SP1 and I'm getting this error quite often. The problem is that it's not even enough to restart VS in order to make it go away, I usually have to restart my pc, and i'm losing a lot of time doing this (it's quite frequent) I've got Windows 7 32bits (can't upgrade to 64 bits, the company doesn't allow it), and I can't do things like creating another solution (please don't reply this :) ) I've used the command to make devenv.exe LARGEADDRESSAWARE, but the error keeps on happening My virtual memory size is set to automatic, and the weird thing is that VS doesn't even take 2gb of ram, so I don't know if the error is really because it's lacking memory, or if it's some bug in the program any ideas, things to try, something?

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  • Image storage as a service

    - by Samuel
    Google App Engine provides a image API for storing / retrieving images. We are currently not in a position to deploy our application on top of App Engine because of limitations in the java frameworks (jboss seam 2.2.0) we are using to build our j2ee application. We would eventually want to deploy our production application on top of Google App Engine, but what are the short term options (java based open source products) which provides comparable functionality to Google App Engine's Image API and will have an easier migration path at a later point in time.

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  • how to check if internal storage file has any data

    - by user3720291
    public class Save extends Activity { int levels = 2; int data_block = 1024; //char[] data = new char[] {'0', '0'}; String blankval = "0"; String targetval = "0"; String temp; String tempwrite; String string = "null"; TextView tex1; TextView tex2; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.save); Intent intent = getIntent(); Bundle b = intent.getExtras(); tex1 = (TextView) findViewById(R.id.textView1); tex2 = (TextView) findViewById(R.id.textView2); if(b!=null) { string =(String) b.get("string"); } loadprev(); save(); } public void save() { if (string.equals("Blank")) blankval = "1"; if (string.equals("Target")) targetval = "1"; temp = blankval + targetval; try { FileOutputStream fos = openFileOutput("data.gds", MODE_PRIVATE); fos.write(temp.getBytes()); fos.close(); } catch (FileNotFoundException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();} tex1.setText(blankval); tex2.setText(targetval); } public void loadprev() { String final_data = ""; try { FileInputStream fis = openFileInput("data.gds"); InputStreamReader isr = new InputStreamReader(fis); char[] data = new char[data_block]; int size; while((size = isr.read(data))>0) { String read_data = String.copyValueOf(data, 0, size); final_data += read_data; data = new char[data_block]; } } catch (FileNotFoundException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();} char[] tempread = final_data.toCharArray();; blankval = "" + tempread[0]; targetval = "" + tempread[1]; } } After much tinkering i have finally managed to get my save/load function to work, but it does have an error, pretty much i got it to work then i did a fresh reintall deleting data.gds, afterwards the save/load function crashes because the data.gds file has no previous values. can i use a if statment to check if data.gds has any values in it, if so how do i do it and if not, then what could i use instead?

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  • Implementing a logging library in .NET with a database as the storage medium

    - by Dave
    I'm just starting to work on a logging library that everyone can use to keep track of any sort of system information while the user is running our application. The simplest example so far is to track Info, Warnings, and Errors. I want all plugins to be able to use this feature, but since each developer might have a different idea of what's important to report, I want to keep this as generic as possible. In the C++ world, I would normally use something like a stl::pair<string,string> to act as a key value pair structure, and have a stl::list of these to act as a "row" in the log. The log cache would then be a list<list<pair<string,string>>> (ugh!). This way, the developers can use a const string key like INFO, WARNING, ERROR to have a consistent naming for a column in the database (for SELECTing specific types of information). I'd like the database to be able to deal with any number of distinct column names. For example, John might have an INFO row with a column called USER, and Bill might have an INFO row with a column called FILENAME. I want the log viewer to be able to display all information, and if one report doesn't have a value for INFO / FILENAME, those fields should just appear blank. So one option is to use List<List<KeyValuePair<String,String>>, and the another is to have the log library consumer somehow "register" its schema, and then have the database do an ALTER TABLE to handle this situation. Yet another idea is to have a table that's just for key value pairs, with a foreign key that maps the key value pairs back to the original log entry. I obviously don't want logging to bog down the system, so I only lock the log cache to make a copy of the data (and remove the already-copied data), then a background thread will dump the information to the database. My specific questions regarding this are: Do you see any performance issues? In other words, have you ever tried something like this and found that certain things just don't work well in practice? Is there a more .NETish way to implement the key value pairs, other than List<List<KeyValuePair<String,String>>>? Even if there is a way to do #2 better, is the ALTER TABLE idea I proposed above a Bad Thing? Would you recommend multiple databases over a single one? I don't yet have an idea of how frequently the log would get written to, but we ideally would like to have lots of low level information. Perhaps there should be a DB with a fixed schema only for the low level stuff, and then another DB that's more flexible for reporting information back to users.

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  • MySql products and categories tables using php and json

    - by Romina Mora
    I have just started learning all this coding language and the teacher is asking us to do the following. I know it may sound really easy for people who do this full time or have more time coding. The teacher is always telling us to GOOGLE everything and I have tried too many sites but I haven't found anything that helps me at all. I need to write two JSON documents (products and categories) using PHP that will dynamically read values from my MySQL database. When each document is called upon, it will return perfectly formatted JSON that will validate using http://jsonlint.com/ Honestly I don't know what to do. I don't understand PHP and now this JSON thing is making it more confusing.

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  • ORACLE: can we create global temp tables or any tables in stored proc?

    - by mrp
    Hi, below is the stored proc I wrote: create or replace procedure test005 as begin CREATE GLOBAL TEMPORARY TABLE TEMP_TRAN ( COL1 NUMBER(9), COL2 VARCHAR2(30), COL3 DATE ) ON COMMIT PRESERVE ROWS / INSERT INTO TEMP_TRAN VALUES(1,'D',sysdate); INSERT INTO TEMP_TRAN VALUES(2,'I',sysdate); INSERT INTO TEMP_TRAN VALUES(3,'s',sysdate); COMMIT; end; when i executed it , i get an error message mentioning: create or replace procedure test005 as begin CREATE GLOBAL TEMPORARY TABLE TEMP_TRAN ( COL1 NUMBER(9), COL2 VARCHAR2(30), COL3 DATE ) ON COMMIT PRESERVE ROWS / INSERT INTO TEMP_TRAN VALUES(1,'D',sysdate); INSERT INTO TEMP_TRAN VALUES(2,'I',sysdate); INSERT INTO TEMP_TRAN VALUES(3,'s',sysdate); COMMIT; end; Error at line 1 ORA-00955: name is already used by an existing object Script Terminated on line 1. I tried to drop the TEMP_TRAN and it says table doesn't exist. So there is no TEMP_TRAN table existed in system. why am I getting this error? I am using TOAD to create this stored proc. Any help would be highly appreciated.

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  • is a mysql temporary table unique for each user accessing the script that creates it...?

    - by SpikETidE
    Hi everyone... While looking for a way to temporarily save the search results when a user searches for a hotel free between particular dates i came across temporary tables. But certain questions are not answered even in mysql manual.... like... Will the temporary table be unique for each user that executes the script...? Or will it be overwritten when two different users run the script at the same time...? When will the table be destroyed..? When the user closes the browser window or just navigates away from the page in which the script runs...? Thanks for your clarifications...

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  • iPhone: Grouped tables and navigation controller issues

    - by Jack Griffiths
    Hi there, I've set up a grouped table on my app, and pushing to new views works fine. Except for one thing. The titles and stack layout are all weird. Here's the breakdown: I have two sections in my table. When I tap on the first row in the first section, it takes me to the correct view, but the title of the new view is the name of the first row in the second section of the table. In turn, the second row in the first section's title is the second row in the second section's title. If I tap on the second row in the second section of the root view table, the navigation button goes to the second row in the first section of the table. So here's a diagram of my table: Table Section 1 Row 1 Row 2 Row 3 Table Section 2 Row A Row B Row C So if I tap on row 3, the title of the pushed view is Row C. The navigation button tells me to go back to Row 3, then eventually ending up at the root view. Here's my implementation file pushing the views: - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath { //CSS if ([[arryClientSide objectAtIndex:indexPath.row] isEqual:@"CSS"]) { CSSViewController *css = [[CSSViewController alloc] initWithNibName:@"CSSViewController" bundle:nil]; [css setTitle:@"CSS"]; [self.navigationController pushViewController:css animated:YES]; } //HTML if ([[arryClientSide objectAtIndex:indexPath.row] isEqual:@"HTML"]) { HTMLViewController *html = [[HTMLViewController alloc] initWithNibName:@"HTMLViewController" bundle:nil]; [html setTitle:@"HTML"]; [self.navigationController pushViewController:html animated:YES]; } //JS if ([[arryClientSide objectAtIndex:indexPath.row] isEqual:@"JavaScript"]) { JSViewController *js = [[JSViewController alloc] initWithNibName:@"JSViewController" bundle:nil]; [js setTitle:@"JavaScript"]; [self.navigationController pushViewController:js animated:YES]; } //PHP if ([[arryServerSide objectAtIndex:indexPath.row] isEqual:@"PHP"]) { PHPViewController *php = [[PHPViewController alloc] initWithNibName:@"PHPViewController" bundle:nil]; [php setTitle:@"PHP"]; [self.navigationController pushViewController:php animated:YES]; } //SQL if ([[arryServerSide objectAtIndex:indexPath.row] isEqual:@"SQL"]) { SQLViewController *sql = [[SQLViewController alloc] initWithNibName:@"SQLViewController" bundle:nil]; [sql setTitle:@"SQL"]; [self.navigationController pushViewController:sql animated:YES]; } & the array feeding the table's data: - (void)viewDidLoad { [super viewDidLoad]; arryClientSide = [[NSArray alloc] initWithObjects:@"CSS",@"HTML",@"JavaScript",nil]; arryServerSide = [[NSArray alloc] initWithObjects:@"Objective-C", @"PHP",@"SQL",nil]; // arryResources = [[NSArray alloc] initWithObjects:@"HTML Colour Codes", @"Useful Resources", @"About",nil]; self.title = @"Select a Language"; [super viewDidLoad]; // Uncomment the following line to display an Edit button in the navigation bar for this view controller. // self.navigationItem.rightBarButtonItem = self.editButtonItem; } Any help would be greatly appreciated. Jack

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  • How to get an id from the results in two tables

    - by Chris Lively
    Consider an order. An order will have one or more line items. Each line item is for a particular product. Given a filter table with a couple of products, how would I get the order id's that had at least all of the products listed in the second table? table Orders( OrderId int ) table LineItems ( OrderId int, LineItemId int, ProductId int ) table Filter ( ProductId int ) data Orders OrderId -------- 1 2 3 LineItems OrderId LineItemId ProductId ------- ---------- --------- 1 1 401 1 2 502 2 3 401 3 4 401 3 5 603 3 6 714 Filter ProductId --------- 401 603 Desired result of the query: OrderId: 3

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  • MySQL Ratings From Two Tables

    - by DirtyBirdNJ
    I am using MySQL and PHP to build a data layer for a flash game. Retrieving lists of levels is pretty easy, but I've hit a roadblock in trying to fetch the level's average rating along with it's pointer information. Here is an example data set: levels Table: level_id | level_name 1 | Some Level 2 | Second Level 3 | Third Level ratings Table: rating_id | level_id | rating_value 1 | 1 | 3 2 | 1 | 4 3 | 1 | 1 4 | 2 | 3 5 | 2 | 4 6 | 2 | 1 7 | 3 | 3 8 | 3 | 4 9 | 3 | 1 I know this requires a join, but I cannot figure out how to get the average rating value based on the level_id when I request a list of levels. This is what I'm trying to do: SELECT levels.level_id, AVG(ratings.level_rating WHERE levels.level_id = ratings.level_id) FROM levels I know my SQL is flawed there, but I can't figure out how to get this concept across. The only thing I can get to work is returning a single average from the entire ratings table, which is not very useful. Ideal Output from the above conceptually valid but syntactically awry query would be: level_id | level_rating 1| 3.34 2| 1.00 3| 4.54 My main issue is I can't figure out how to use the level_id of each response row before the query has been returned. It's like I want to use a placeholder... or an alias... I really don't know and it's very frustrating. The solution I have in place now is an EPIC band-aid and will only cause me problems long term... please help!

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  • can oracle types be updated like tables?

    - by Omnipresent
    I am converting GTT's to oracle types as explained in an excellent answer by APC. however, some GTT's are being updated based on a select query from another table. For example: UPDATE my_gtt_1 c SET (street, city, STATE, zip) = (SELECT src.unit_address, src.unit_city, src.unit_state, src.unit_zip_code FROM (SELECT mbr.ROWID row_id, unit_address, RTRIM(a.unit_city) unit_city, RTRIM(a.unit_state) unit_state, RTRIM(a.unit_zip_code) unit_zip_code FROM table_1 b, table_2 a, my_gtt_1 mbr WHERE type = 'ABC' AND id = b.ssn_head AND a.h_id = b.h_id AND row_id >= v_start_row AND row_id <= v_end_row) src WHERE c.ROWID = src.row_id) WHERE state IS NULL OR state = ' '; if my_gtt_1 was not a global temporary table but an oracle collection type then is it possible to do updates this complex? Or in these cases we are better off using the global temporary table?

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  • .Net 4.0 Memory-Mapped Files verses RDMS Storage

    - by Harry
    I'm interested in people's thoughts comparing storing data in a traditional SQL based Database or utilising a Memory-Mapped File such as the one in the new .Net 4.0 runtime. The data in question would be arrays of simple structures. Obvious pros and cons: SQL Database Pros Adhoc query support SQL Management Tools Schema changes (adding more columns and setting default values) Memory-Mapped Pros Lighter overhead? (this is an assumption on my part) Shareable between process threads Any others? Is it worth it for performance gains?

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  • JQuery Validate Dynamic Table

    - by Richard
    I'm using the JQuery validation plug to validate my entire form. I also have a dynamic table on my registration page where the user can register more people. I can validate the rest of the form fine but my goal is to validate the table inputs just the same. Here is my jfiddle code: tables I don't know why the add line won't work there but it definitely works on my page. Anyway, that code ends up validate ONLY the first row of my table, but I want it to validate every single row. Can anyone see any problems with the code?

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  • Questions about using git as a backend storage system

    - by XO
    New to git here... I want to commit my personal file share to a git repo (text, docs, images etc). As I make modifications to various files over time, telling git about them along the way, how do go about things so I can: Get out of the business of traditional fulls/incrementals. Be able to do a point-in-time file or full clone restore. Basically, I want something granular, such that, if I make an edit to a file 5 times on a particular day. I will have 5 versions of that file that I can refer back to- forever. Or even just derive the a full copy of everything the way it looked on that particular day. I am currently using rsync for remote incremental syncs (no file versioning).

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  • Unable to relate two MySQL tables (foreign keys)

    - by KPL
    Hello people, Here's my USER table CREATE TABLE IF NOT EXISTS `users` ( `id` int(11) NOT NULL AUTO_INCREMENT, `username` varchar(100) NOT NULL, `expiry` varchar(6) NOT NULL, `contact_id` int(11) NOT NULL, `email` varchar(255) NOT NULL, `password` varchar(100) NOT NULL, `level` int(3) NOT NULL, `active` tinyint(4) NOT NULL DEFAULT '1', PRIMARY KEY (`id`,`email`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ; And here's my contact_info table CREATE TABLE IF NOT EXISTS `contact_info` ( `id` int(11) NOT NULL AUTO_INCREMENT, `name` varchar(255) NOT NULL, `email_address` varchar(255) NOT NULL, `company_name` varchar(255) NOT NULL, `license_number` varchar(255) NOT NULL, `phone` varchar(30) NOT NULL, `fax` varchar(30) NOT NULL, `mobile` varchar(30) NOT NULL, `category` varchar(100) NOT NULL, `country` varchar(20) NOT NULL, `state` varchar(20) NOT NULL, `city` varchar(100) NOT NULL, `postcode` varchar(50) NOT NULL, PRIMARY KEY (`id`,`email_address`), ) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ; The system uses username to login users.I want to modify it in such a way that it uses email for login. But there's no email_address in users table. I have added foreign key - email in user table(which is email_address in contact_info). How should I query database?

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  • Foreign key pointing to different tables

    - by Álvaro G. Vicario
    I'm implementing a table per subclass design I discussed in a previous question. It's a product database where products can have very different attributes depending on their type, but attributes are fixed for each type and types are not manageable at all. I have a master table that holds common attributes: product_type ============ product_type_id INT product_type_name VARCHAR E.g.: 1 'Magazine' 2 'Web site' product ======= product_id INT product_name VARCHAR product_type_id INT -> Foreign key to product_type.product_type_id valid_since DATETIME valid_to DATETIME E.g. 1 'Foo Magazine' 1 '1998-12-01' NULL 2 'Bar Weekly Review' 1 '2005-01-01' NULL 3 'E-commerce App' 2 '2009-10-15' NULL 4 'CMS' 2 '2010-02-01' NULL ... and one subtable for each product type: item_magazine ============= item_magazine_id INT title VARCHAR product_id INT -> Foreign key to product.product_id issue_number INT pages INT copies INT close_date DATETIME release_date DATETIME E.g. 1 'Foo Magazine Regular Issue' 1 89 52 150000 '2010-06-25' '2010-06-31' 2 'Foo Magazine Summer Special' 1 90 60 175000 '2010-07-25' '2010-07-31' 3 'Bar Weekly Review Regular Issue' 2 12 16 20000 '2010-06-01' '2010-06-02' item_web_site ============= item_web_site_id INT name VARCHAR product_id INT -> Foreign key to product.product_id bandwidth INT hits INT date_from DATETIME date_to DATETIME E.g. 1 'The Carpet Store' 3 10 90000 '2010-06-01' NULL 2 'Penauts R Us' 3 20 180000 '2010-08-01' NULL 3 'Springfield Cattle Fair' 4 15 150000 '2010-05-01' '2010-10-31' Now I want to add some fees that relate to one specific item. Since there are very little subtypes, it's feasible to do this: fee === fee_id INT fee_description VARCHAR item_magazine_id INT -> Foreign key to item_magazine.item_magazine_id item_web_site_id INT -> Foreign key to item_web_site.item_web_site_id net_price DECIMAL E.g.: 1 'Front cover' 2 NULL 1999.99 2 'Half page' 2 NULL 500.00 3 'Square banner' NULL 3 790.50 4 'Animation' NULL 3 2000.00 I have tight foreign keys to handle cascaded editions and I presume I can add a constraint so only one of the IDs is NOT NULL. However, my intuition suggests that it would be cleaner to get rid of the item_WHATEVER_id columns and keep a separate table: fee_to_item =========== fee_id INT -> Foreign key to fee.fee_id product_id INT -> Foreign key to product.product_id item_id INT -> ??? But I can't figure out how to create foreign keys on item_id since the source table varies depending on product_id. Should I stick to my original idea?

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  • problem downloading movie to iphone for storage and playback

    - by padatronic
    I am basically making a video library where you download videos and I then write them to the applications documents folder. This all works fine and if i stream the video from online it plays fine. Or indeed I can stream it from the resource folder fine. However, after downloading it and saving to the documents folder then attempting to stream I get the error 'movie format not supported' any ideas? thanks very much

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  • Using Excel VBA to Create SQL Tables

    - by user307655
    Hi All, I am trying to use Excel VBA to automate the creation of a SQL table in an existing SQL Database. I have come across the following code on this side. Private Sub CreateDatabaseFromExcel() Dim dbConnectStr As String Dim Catalog As Object Dim cnt As ADODB.Connection Dim dbPath As String Dim tblName As String 'Set database name in the Excel Sheet dbPath = ActiveSheet.Range("B1").Value 'Database Name tblName = ActiveSheet.Range("B2").Value 'Table Name dbConnectStr = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & dbPath & ";" 'Create new database using name entered in Excel Cell ("B1") Set Catalog = CreateObject("ADOX.Catalog") Catalog.Create dbConnectStr Set Catalog = Nothing 'Connect to database and insert a new table Set cnt = New ADODB.Connection With cnt .Open dbConnectStr .Execute "CREATE TABLE tblName ([BankName] text(50) WITH Compression, " & _ "[RTNumber] text(9) WITH Compression, " & _ "[AccountNumber] text(10) WITH Compression, " & _ "[Address] text(150) WITH Compression, " & _ "[City] text(50) WITH Compression, " & _ "[ProvinceState] text(2) WITH Compression, " & _ "[Postal] text(6) WITH Compression, " & _ "[AccountAmount] decimal(6))" End With Set cnt = Nothing End Sub However i can't successfully get it to work? What I am trying to do is actually use Excel to create a table not a database? The database already exists. I would just like to create a new table. The name of the table will be referenced from cell A1 in Sheet 1. Can somebody please help. Thanks Regards Gerard

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  • Rails: using find method to access joined tables for polymorphic relationships

    - by DJTripleThreat
    Ok, I have a generic TimeSlot model that deals with a start_at and an end_at for time spans. A couple models derive from this but I'm referring to one in this question: AppointmentBlock which is a collection of Appointments. I want to validate an AppointmentBlock such that no other AppointmentBlocks have been scheduled for a particular Employee in the same time frame. Since AppointmentBlock has a polymorphic association with TimeSlot, you have to access the AppointmentBlock's start_at and end_at through the TimeSlot like so: appt_block.time_slot.start_at This means that I need to have some kind of join in my :conditions for my find() method call. Here is my code so far: #inside my appointment_block.rb model validate :employee_not_double_booked def employee_not_double_booked unless self.employee_id # this find's condition is incorrect because I need to join time_slots to get access # to start_at and end_at. How can I do this? blocks = AppointmentBlock.find(:first, :conditions => ['employee_id = ? and (start_at between ? and ? or end_at between ? and ?)', self.employee_id, self.time_slot.start_at, self.time_slot.end_at, self.time_slot.start_at, self.time_slot.end_at]) # pseudo code: # collect a list of appointment blocks that end after this # apointment block starts or start before this appointment # block ends that are also associated with this appointment # blocks assigned employee # if the count is great then 0 the employee has been double # booked. # if a block was found that means this employee is getting # double booked so raise an error errors.add "AppointmentBlock", "has already been scheduled during this time" if blocks end end Since AppointmentBlock doesn't have a start_at or an end_at how can I join with the time_slots table to get those conditions to work?

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