Now that "NOSQL" or "object only" storage systems like MongoDB or memcached are really picking up steam in the world. I was wondering if there are any requests that cannot be performed on them that can be performed using multiple object joins (in SQL that is JOIN "table"). In other words, are there any multi-table queries that cannot be ...
I am planning to create a pricing matrix for a project in Rails. It's supposed to be a table of destinations and departure locations, and prices depending on where you came and are planning to go. I am kinda undecided on how to better do this: either making a table in the db for this matrix, or making a mega array of constants. Problem ...
I am thinking of developing a search engine, but have no idea about the backend that i could use efficiently. Please suggest me a database in which i can store thousands of records and query them in a time efficient manner. I am developing search engine for my own interest so, please dont give me any critics thoughts as usually found in ...
I have a Django web application that's similar to the typical Q&A system. A user asks a question. other users submit answers to that question: Each user is allowed to submit up to N answers to each question, where N > 1 (so, say each user can submit no more than 3 answers to each question) A user can edit his existing answers, or sub...
Is there an easy way to define an operator alias for the = operator in PostgreSQL? How is that solved for the != and <> operator? Only the <> operator seems to be in pg_operators. Is the != operator hard-coded? This is needed for an application which uses a self-defined operator. In most environments this operator should act like a =, ...
The Google page on uploading and downloading datastores is pretty useless, but I've gotten this far. Now I need to get the data in the .sql3 into whatever database it was originally stored in. ...
I have two tables, one is signups and contained in it are two fields, firstchoice, and secondchoice. Another is a schedule table, and it has things like a begin and end date, and a semesterid. firstchoice and secondchoice from the signups table both reference the semesterid from the schedule table. I am trying to create a page which d...
I'm following a tutorial by Scott Gu that refers to a class named DbContext. I can't find it on any namespace on framework 4 and it seems to me it was renamed from CT4 DbContext to .net4 System.Data.Linq.DataContext. Is my assumption correct? ...
Over the years I have read a lot of people's opinions on how to get better performance out of their SQL (Microsoft SQL Server, just so we are all on the same page...) queries. However, they all seem to be tightly tied to either a high-performance OLTP setup or a data warehouse OLAP setup (cubes-galore...). However, my situation today is ...
Hi, How can I combine 2 group by conditions? I have records for each id for every hour in a day and I want to group information by first id and all records for that id in that day then second id and all records for that in the day. My sample query is this: SELECT r.name , r.network , r.namestring , i.name , i.description ,...
Hello, I have large data set, which I want to query. The query does not change but the underlying data does. From what I read, I could construct a "view" and query it. Also, I read that Couch DB knows how to update the view when data is changed so I assume querying the view again would be still fast. My questions are, do I understand C...
Hello I would like to produce a list of dates based on a user determined "start date", over a 12 week period. If a user selects today's date, I need to know each date from today over 12 weeks. Once I have these dates, I would need to insert them into a DB table. I'd like to say I've made some in-roads into how to do this, I reckon ...
Hi I am doing an assignment on ER modelling and there is a part that I'm stuck on, here is an extract: Patient is a person who is either admitted to the hospital or is registered in an outpatient program. Each patient has a patient number (ID), name, dob, and tele. Resident patients have a Date Admitted. Each outpatient is scheduled for...
Hi, I need somebody to point me to the right direction, I have a MS Access DB that is updated by HP devices, and I have to sync it with the SQL Server 2008. I have a few Ideas, and I would like to know what do you think about this: Is there anything like triggers on access? if so can I comunicate with a SQL Server? Is there any way to...
I am trying to find the path for the android database files on Ubuntu 10.4, because I want to access with SQLite Browser. Someone can tell? ...
I have a winforms app that uses sqlite to store data. Instead of shipping a blank database, can I use scripts to create the tables the first time the user uses the app? Can you point to a C# example? Update: I want to avoid shipping a blank database. So if a user install the app for 1 user only, only his profile gets a copy. All users p...
SELECT a FROM b UNION ALL SELECT a FROM c UNION ALL SELECT a FROM d Does UNION ALL guarantee to print out records from tables b, c, d in that order? I.e., no records from c before any from b. This question is not for a specific DBMS. ...
Consider the following sample table in MySQL: CREATE TABLE transactions ( transId BIGINT NOT NULL AUTO_INCREMENT, transDate DATETIME NOT NULL, transTotal DECIMAL(10,2), PRIMARY KEY (transId) ); This table is used in high volume operations i.e. lots of INSERTS. You will eventually reach the maximum limit of transId. ...
Hello everyone, I would like to know if there is any tool able to extract the design from an existing Oracle database. I have a read access to it and I would like to have the design. Or simply export it to a *.sql and then read it with any tool able to create the design with the links between the tables. Something like that Thank you...
Hello, since it is possible to do: INSERT INTO some_table VALUES (NEW.*) in pl/pgsql can we do something similar but for UPDATE clause using NEW ? I mean i want to update some row using values from NEW object. Thanks in advance. ...