Search Results

Search found 5520 results on 221 pages for 'compound primary'.

Page 56/221 | < Previous Page | 52 53 54 55 56 57 58 59 60 61 62 63  | Next Page >

  • mysql GROUP_CONCAT

    - by user301766
    I want to list all users with their corropsonding user class. Here are simplified versions of my tables CREATE TABLE users ( user_id INT NOT NULL AUTO_INCREMENT, user_class VARCHAR(100), PRIMARY KEY (user_id) ); INSERT INTO users VALUES (1, '1'), (2, '2'), (3, '1,2'); CREATE TABLE classes ( class_id INT NOT NULL AUTO_INCREMENT, class_name VARCHAR(100), PRIMARY KEY (class_id) ); INSERT INTO classes VALUES (1, 'Class 1'), (2, 'Class 2'); And this is the query statement I am trying to use but is only returning the first matching user class and not a concatenated list as hoped. SELECT user_id, GROUP_CONCAT(DISTINCT class_name SEPARATOR ",") AS class_name FROM users, classes WHERE user_class IN (class_id) GROUP BY user_id; Actual Output +---------+------------+ | user_id | class_name | +---------+------------+ | 1 | Class 1 | | 2 | Class 2 | | 3 | Class 1 | +---------+------------+ Wanted Output +---------+---------------------+ | user_id | class_name | +---------+---------------------+ | 1 | Class 1 | | 2 | Class 2 | | 3 | Class 1, Class 2 | +---------+---------------------+ Thanks in advance

    Read the article

  • MySQL INSERT data does not get stored in proper db, only temporary?

    - by greye
    I'm having trouble with MySQL or Python and can't seem to isolate the problem. INSERTs only seem to last the run of the script and are not stored in the database. I have this script: import MySQLdb db = MySQLdb.connect(host="localhost", user="user", passwd="password", db="example") dbcursor = db.cursor() dbcursor.execute("select * from tablename") temp = dbcursor.fetchall() print 'before: '+str(temp) dbcursor.execute('INSERT INTO tablename (data1, data2, data3) VALUES ("1", "a", "b")') dbcursor.execute("select * from tablename") temp = dbcursor.fetchall() print 'after: '+str(temp) The first time I run it I get the expected output: >>> before: () after: ((1L, 'a', 'b'),) The problem is that if I run it again, the before comes out empty when it should already have the entry in it and the after doesn't break (data 1 is primary key). >>> before: () after: ((1L, 'a', 'b'),) >>> before: () after: ((1L, 'a', 'b'),) >>> before: () after: ((1L, 'a', 'b'),) If I try running the insert command twice in the same script it will break ("Duplicate entry for PRIMARY KEY") Any idea what might be happening here?

    Read the article

  • What is the meanning of 'idx_categories_desc_categories_name' in osCommerce

    - by Sumant
    while working on osCommerce-3 i got the table structure for category & categories_description as CREATE TABLE IF NOT EXISTS `osc_categories` ( `categories_id` int(10) unsigned NOT NULL AUTO_INCREMENT, `categories_image` varchar(255) DEFAULT NULL, `parent_id` int(10) unsigned DEFAULT NULL, `sort_order` int(11) DEFAULT NULL, `date_added` datetime DEFAULT NULL, `last_modified` datetime DEFAULT NULL, PRIMARY KEY (`categories_id`), KEY `idx_categories_parent_id` (`parent_id`) ) ENGINE=MyISAM DEFAULT CHARSET=utf8 AUTO_INCREMENT=5 ; CREATE TABLE IF NOT EXISTS `osc_categories_description` ( `categories_id` int(10) unsigned NOT NULL, `language_id` int(10) unsigned NOT NULL, `categories_name` varchar(255) NOT NULL, PRIMARY KEY (`categories_id`,`language_id`), KEY `idx_categories_desc_categories_id` (`categories_id`), KEY `idx_categories_desc_language_id` (`language_id`), KEY `idx_categories_desc_categories_name` (`categories_name`) ) ENGINE=MyISAM DEFAULT CHARSET=utf8; here i am not getting the meanning of indexing "idx_categories_desc_categories_id", "idx_categories_desc_language_id", "idx_categories_desc_categories_name" What is the use of this indexing.What does it mean?

    Read the article

  • How to catch specific exception without error number?

    - by CJ7
    I need to catch the following specific exception: System.Data.OleDb.OleDbException was caught ErrorCode=-2147467259 Message="The changes you requested to the table were not successful because they would create duplicate values in the index, primary key, or relationship. Change the data in the field or fields that contain duplicate data, remove the index, or redefine the index to permit duplicate entries and try again." Source="Microsoft JET Database Engine" I'm not sure what ErrorCode is but it looks unreliable. Can I rely on Message being identical across platforms? Is the only solution to do a text search of Message for words like duplicate and primary key? Note: see my question here for why I need to catch this exception.

    Read the article

  • [Django] How to find out whether a model's column is a foreign key?

    - by codethief
    I'm dynamically storing information in the database depending on the request: // table, id and column are provided by the request table_obj = getattr(models, table) record = table_obj.objects.get(pk=id) setattr(record, column, request.POST['value']) The problem is that request.POST['value'] sometimes contains a foreign record's primary key (i.e. an integer) whereas Django expects the column's value to be an object of type ForeignModel: Cannot assign "u'122'": "ModelA.b" must be a "ModelB" instance. Now, is there an elegant way to dynamically check whether b is a column containing foreign keys and what model these keys are linked to? (So that I can load the foreign record by it's primary key and assign it to ModelA?) Or doesn't Django provide information like this to the programmer so I really have to get my hands dirty and use isinstance() on the foreign-key column?

    Read the article

  • Compare rows between 2 tables

    - by arthur
    I am new to SQL and I need to build a database for a grocery store(not real, just a course assignment) i have two fields from two different tables - supplied price - the price that the store buys from the supplier and price that is given to the customers How can I make a constraint that insures that supplied price is lower then the price that is given to the customers? The relevant tables that I have are: CREATE TABLE Supplied_Products( [Supplier ID] Int NOT NULL Foreign Key References Suppliers, [Product ID] Int NOT NULL Foreign Key References Products, Price Float NOT NULL, CHECK (Price0), Constraint PK_Supplied_Products PRIMARY KEY([Supplier ID] ,[Product ID]) ) CREATE TABLE Products( [Product-ID] Int NOT NULL PRIMARY KEY, [Product Name] Varchar(20) NOT NULL, Price Float NOT NULL, [Category-Name] Varchar(20) NOT NULL Foreign Key References Categories, [Weight] Float NOT NULL, [Is Refrigirated] Varchar(1) DEFAULT 'N' CHECK ([Is Refrigirated] in('Y','N')),/* Is Refrigirated can be only Y-yes or N-no*/ CHECK (Price 0) )

    Read the article

  • WindowStartupLocation.CenterScreen is opening my window on the wrong display

    - by chaiguy
    According to the documentation, CenterScreen should open the window in the center of the screen that contains the mouse cursor, however this is not happening. I have a dual monitor setup, with my secondary monitor appearing to the left of my primary monitor (the one with the task bar). When the user clicks a link in my interface on the primary (right-most) monitor, and I open a new window with WindowStartupLocation set to CenterScreen, the window appears in the center of the screen of the left monitor. This is not where the mouse is and I am lost as to why it is picking that display. Has anyone experienced this before or have any ideas for a workaround? If I can't get the proper behavior using WindowStartupLocation, I will just manually move the window to the proper display (I still have to figure that out though).

    Read the article

  • How to expose an entity via alternate keys with spring data rest

    - by dan carter
    Spring-data-rest does a great job exposing entities via their primary key for GET, PUT and DELETE etc. operations. /myentityies/123 It also exposes search operations. /myentities/search/byMyOtherKey?myOtherKey=123 In my case the entities have a number of alternate keys. The systems calling us, will know the objects by these IDs, rather than our internal primary key. Is it possible to expose the objects via another URL and have the GET, PUT and DELETE handled by the built-in spring-data-rest controllers? /myentities/myotherkey/456 We'd like to avoid forcing the calling systems to have to make two requests for each update. I've tried playing with @RestResource path value, but there doesn't seem to be a way to add additional paths.

    Read the article

  • mysql foreign key problem.

    - by JP19
    Hi, What is wrong with the foreign key addition here: mysql> create table notes ( id int (11) NOT NULL auto_increment PRIMARY KEY, note_type_id smallint(5) NOT NULL, data TEXT NOT NULL, created_date datetime NOT NULL, modified_date timestamp NOT NULL on update now()) Engine=InnoDB; Query OK, 0 rows affected (0.08 sec) mysql> create table notetypes ( id smallint (5) NOT NULL auto_increment PRIMARY KEY, type varchar(255) NOT NULL UNIQUE) Engine=InnoDB; Query OK, 0 rows affected (0.00 sec) mysql> alter table `notes` add constraint foreign key(`note_type_id`) references `notetypes`.`id` on update cascade on delete restrict; ERROR 1005 (HY000): Can't create table './admin/#sql-43e_b762.frm' (errno: 150) Thanks JP

    Read the article

  • How to structure (normalize?) a database of physical parameters?

    - by Arrieta
    Hello: I have a collection of physical parameters associated with different items. For example: Item, p1, p2, p3 a, 1, 2, 3 b, 4, 5, 6 [...] where px stands for parameter x. I could go ahead and store the database exactly as presented; the schema would be CREATE TABLE t1 (item TEXT PRIMARY KEY, p1 FLOAT, p2 FLOAT, p3 FLOAT); I could retrieve the parameter p1 for all the items with the statement: SELECT p1 FROM t1; A second alternative is to have an schema like: CREATE TABLE t1 (id INT PRIMARY KEY, item TEXT, par TEXT, val FLOAT) This seems much simpler if you have many parameters (as I do). However, the parameter retrieval seems very awkward: SELECT val FROM t1 WHERE par == 'p1' What do you advice? Should go for the "pivoted" (first) version or the id, par, val (second) version? Many thanks.

    Read the article

  • IDENTITY_INSERT is set to off error

    - by kingrichard2005
    I have a MVC web application with a table in the model that I would like to add to. I have the primary key set along with the other data fields, but every time I try to add to the table, I get the following error: "Cannot insert explicit value for identity column in table 'TABLE_NAME' when IDENTITY_INSERT is set to OFF." I'm not sure why this problem is coming up, I have the primary key set as the identity and it is also set to auto increment in the Visual Studio table designer. Is there any way I can adjust the IDENTITY_INSERT parameter in the table designer in Visual Studio?? Or is there some other issue that might be causing this.

    Read the article

  • Copying Data between table without identity column

    - by user668479
    I have two table and I need to copy the data across from SRCServiceUsers to Clients Everytime i run it I get the following: Violation of PRIMARY KEY constraint 'PK_Clients'. Cannot insert duplicate key in object 'dbo.Clients'. The statement has been terminated. The Primary key ClientId field is not an identity column and therefore requires filling To date I have the following insert into Clients( ClientID, Title, Forenames, FamilyName, [Address], Town, County, PostCode, PhoneNumber, StartDate) SELECT ( Select Max(Clients.ClientID)+ 1, SRCServiceUsers.Title, SRCServiceUsers.[First Names], SRCServiceUsers.Surname, --BUILD UP MUITIPLE COLUMNS SRCServiceUsers.[Property Name] + ', ' + SRCServiceUsers.Street + ', ' + SRCServiceUsers.Suburb as [Address], SRCServiceUsers.Town, SRCServiceUsers.County, SRCServiceUsers.Postcode, SRCServiceUsers.Telephone, SRCServiceUsers.[Start Date] From srcsERVICEuSERS How can i autoincrement the PK field - CLientID when inserting the data? Many thanks Andrew

    Read the article

  • @SequenceGenerator - allocationSize, reverse engineering with Eclipse Hibernate Tools

    - by Spooky
    I use the Eclipse Hibernate Tools to create domain classes with JPA annotations from my Oracle database. To control sequence generation I have added the following entry to the hibernate.reveng.xml: ... <primary-key> <generator class="sequence"> <param name="sequence">SEQ_FOO_ID</param> </generator> </primary-key> ... This results in the following annotation: @SequenceGenerator(name = "generator", sequenceName = "SEQ_FOO_ID") However I need to set the "allocationSize" like this: @SequenceGenerator(name = "generator", sequenceName = "SEQ_FOO_ID", allocationSize = 1) Is it possible to set this somehow in the hibernate.reveng.xml?

    Read the article

  • Database indexes and their Big-O notation

    - by miket2e
    I'm trying to understand the performance of database indexes in terms of Big-O notation. Without knowing much about it, I would guess that: Querying on a primary key or unique index will give you a O(1) lookup time. Querying on a non-unique index will also give a O(1) time, albeit maybe the '1' is slower than for the unique index (?) Querying on a column without an index will give a O(N) lookup time (full table scan). Is this generally correct ? Will querying on a primary key ever give worse performance than O(1) ? My specific concern is for SQLite, but I'd be interested in knowing to what extent this varies between different databases too.

    Read the article

  • HBase as web app backend

    - by NathanD
    Can anyone advise if it is a good idea to have HBase as primary data source for web-based application? My primary concern is HBase's response time to queries. Is it possible to have sub-second response? edit: more details about the app itself. Amount of data: ~500GB of text data, expect to reach 1TB soon Number of concurrent users using the app: up to 50 The app will be used to present reports about data stored in HBase, like how many times keyword "X" occured in last 24h. For ~80% of requests from that app I will know the exact key, 20% will be scans (I'm looking into HBase schema design related topics to make it run fast)

    Read the article

  • Data model for timesheet to task and/or timesheet to project?

    - by John
    Let's say I want to make a simple project tracking system. A manager can create a project. Then he can create tasks for that project. Team members can record the hours they work for each task or for the project as a whole. Is the following design for the t_timesheet table a good idea? timesheet_id - primary key, autoincrement project_id - not null, foreign key constraint to t_project task_id - nullable, foreign key constraint to t_task user_id - not null, foreign key constraint to t_user hours - decimal Or should I do something like this: timesheet_id - primary key, autoincrement task_id - not null, foreign key constraint to t_task user_id - not null, foreign key constraint to t_user hours - decimal In the second option, I intend to always have a record in t_task labelled "miscellaneous items" with a foreign key to the relevant t_project record. Then I'll be able to track all hours for a project that aren't for any particular task. Are any of the ideas above good? What would be better?

    Read the article

  • 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?

    Read the article

  • Files and filegroups sql server 2005

    - by Dhivagar
    Can we move default file to another filegroup. sample code is given below Sample code create database EMPLOYEE ON PRIMARY ( NAME = 'PRIMARY_01', FILENAME = 'C:\METADATA\PRIM01.MDF', SIZE = 5 MB , MAXSIZE =50 MB, FILEGROWTH = 2 MB), ( NAME = 'SECONDARY_02', FILENAME = 'C:\METADATA\SEC02.NDF' ), FILEGROUP EMPLOYEE_dETAILS ( NAME = 'EMPDETILS_01', FILENAME = 'C:\METADATA\EMPDET01.NDF', SIZE = 5 MB , MAXSIZE =50 MB, FILEGROWTH = 2 MB), ( NAME = 'EMPDETILS_02', FILENAME = 'C:\METADATA\EMPDET02.NDF', SIZE = 5 MB , MAXSIZE =50 MB, FILEGROWTH = 2 MB) LOG ON ( NAME = 'TRANSACLOG', FILENAME ='c:\METADATA\TRAS01.LDF', SIZE = 5 MB , MAXSIZE =50 MB, FILEGROWTH = 2 MB ) now i want to move the FILENAME = 'C:\METADATA\SEC02.NDF' from deault primary file to the FILEGROUP EMPLOYEE_dETAILS ? need assist ??

    Read the article

  • The conceptual process of populating related tables in a database (MySql) from a CSV file

    - by user322772
    I'm new to relational databases and all the material I've read covered primary and foreign keys, normal forms, and joins but left out to populate the database once it's created. How do you import a CSV file so the fields match their related table? Say you were tying to build a beer database and had a CSV file with each line as a record. Header: brewer, beer_name, country, city, state, beer_category, beer_type, alcohol_content Record 1: Anheuser-Busch, Budweiser, United States, St. Louis, Mo, Pale lager, Regular, 5.0% Record 2: Anheuser-Busch, Bud Light, United States, St. Louis, Mo, Pale lager Light, 4.2% Record 3: Miller Brewing Company, Miller Lite, United States, Milwaukee, WI, Pale lager, Light, 4.2% You can create a "Brewer" table and a "Beer" table. When importing how does you connect the primary keys between the tables?

    Read the article

  • Postgresql count+sort performance

    - by invictus
    I have built a small inventory system using postgresql and psycopg2. Everything works great, except, when I want to create aggregated summaries/reports of the content, I get really bad performance due to count()'ing and sorting. The DB schema is as follows: CREATE TABLE hosts ( id SERIAL PRIMARY KEY, name VARCHAR(255) ); CREATE TABLE items ( id SERIAL PRIMARY KEY, description TEXT ); CREATE TABLE host_item ( id SERIAL PRIMARY KEY, host INTEGER REFERENCES hosts(id) ON DELETE CASCADE ON UPDATE CASCADE, item INTEGER REFERENCES items(id) ON DELETE CASCADE ON UPDATE CASCADE ); There are some other fields as well, but those are not relevant. I want to extract 2 different reports: - List of all hosts with the number of items per, ordered from highest to lowest count - List of all items with the number of hosts per, ordered from highest to lowest count I have used 2 queries for the purpose: Items with host count: SELECT i.id, i.description, COUNT(hi.id) AS count FROM items AS i LEFT JOIN host_item AS hi ON (i.id=hi.item) GROUP BY i.id ORDER BY count DESC LIMIT 10; Hosts with item count: SELECT h.id, h.name, COUNT(hi.id) AS count FROM hosts AS h LEFT JOIN host_item AS hi ON (h.id=hi.host) GROUP BY h.id ORDER BY count DESC LIMIT 10; Problem is: the queries runs for 5-6 seconds before returning any data. As this is a web based application, 6 seconds are just not acceptable. The database is heavily populated with approximately 50k hosts, 1000 items and 400 000 host/items relations, and will likely increase significantly when (or perhaps if) the application will be used. After playing around, I found that by removing the "ORDER BY count DESC" part, both queries would execute instantly without any delay whatsoever (less than 20ms to finish the queries). Is there any way I can optimize these queries so that I can get the result sorted without the delay? I was trying different indexes, but seeing as the count is computed it is possible to utilize an index for this. I have read that count()'ing in postgresql is slow, but its the sorting that are causing me problems... My current workaround is to run the queries above as an hourly job, putting the result into a new table with an index on the count column for quick lookup. I use Postgresql 9.2.

    Read the article

  • Get the BindingSource position based on DataTable row

    - by Ronald
    I have a datatable that contains the rows of a database table. This table has a primary key formed by 2 columns. The components are assigned this way: datatable - bindingsource - datagridview. What I want is to search a specific row (based on the primary key) to select it on the grid. I cant use the bindingsource.Find method because you only can use one column. I have access to the datatable, so I do manually search on the datatable, but how can I get bindingsource row position based on the datatable row? Or there is another way to solve this? Im using Visual Studio 2005, VB.NET.

    Read the article

< Previous Page | 52 53 54 55 56 57 58 59 60 61 62 63  | Next Page >