I have an mnesia table with three fields, i, a and b, created using the record -record(rec, {i, a,b}). Now I insert a row into the table as: mnesia:transaction( fun() -> mnesia:write("T", #rec{i=1, a=2, b=3}, write) end ). Now what do I do if I want to update this row, and change only the value of a to 10, while leaving i and b wit...
Is there a paradigm in which I can change a data-key name in one place and one place only, and have it properly be dealt with by both the application and database? I have resorted most recently to using class constants to map to database field names, but I still have to keep those aligned with the raw database keys. What I mean is, us...
The development machine I work on has Ubuntu Jaunty Jackalope as its operating system. I have been presented with data for a project I'm working on in the form of an .accdb file created by Microsoft Access. I do not own a copy of Microsoft Access. I do have Open Office installed and would be willing to install any software package ava...
I am working in a small law firm and my boss has asked me to put a database together to help with outgoing mail. There are 5 different tables that exist in Access. (Applicants, Attorneys, Lien Claimants, Employers and Workers Compensation Boards) All of the tables include addresses only. Each Applicant has an attorney, one or possibly...
Hello, I need to store scientific information in a database (sql server). What is the best way to store a value in a database where "smaller than", larger than" is part of the information. Example: PatientId: 123 Mutation rate: <3% PatientId: 999 Mutation rate: 3% PatientId: 456 Mutation rate: 10% I need to be able to sort and filt...
I'm having a weird problem with my web application when it is hosted on Azure. Basically the issue is that I have one page that goes to the database and when my application's connection string points to my SQL Azure DB, I get a blank response for that particular page (By blank I mean when you view source you see absolutely nothing). Wh...
Hello All, I'm using the following code to populate a DataGridView (sqliteAdapter derives from DbDataAdapter): sqliteAdapter.SelectCommand.CommandText = SQLCommand; sqliteConn.Open(); using (DataTable dt = new DataTable()) { sqLiteAdapter.Fill(dt); dataGridRes.DataSource = dt; } The Actual SQLCommand is: SELECT Email NOTNULL...
When should I use a composite index in a database? What are the performance ramification by using a composite index)? Why should I use use a composite index? For example, I have a homes table: CREATE TABLE IF NOT EXISTS `homes` ( `home_id` int(10) unsigned NOT NULL auto_increment, `sqft` smallint(5) unsigned NOT NULL, `year_bui...
Earlier on while I was working on my databases, I wondered if using a case sensitive collation like utf8_bin would increase performance over case insensitive collaction like utf8_general_ci (examples are from MySQL). Does anyone have any comment on this? What about databases other than MySQL? ...
Hi guys, i have database with larger number of records.(database values are updated via a webservice) Each record/row is of type (id,xmlfilename,operation,parameters,operationId,status) ie. we have perform operation as specified by'operation' on a xmlfile specified by "xmlfilename" with parameters for operation specified by "parameter...
Hi Folks, is there any way to move an column in an oracle table from last to first position? Someone has dropped the ID column, and recreated it. So now it is at the end, wich is an problem because some of our PHP Scripts are using the first column as identifier (one Abstract Model with more than 100 other Models using this base object....
I am using JMeter to test our application 's performance. but I found when I send 20 requests from JMeter, with this the reason result should be add 20 new records into the sql server, but I just find 5 new records, which means that SQL server discard the other requests(because I took a log, and make sure that the insert new records are ...
I used Linq to insert objects into database.But if i used threads to simultanously create 20 object within 1 second, then system will fail to add 20 objects into database. And I found it is not because of the sql server 's limit. so the only possible is Linq, any one have idea ? How can I create 20 records or more in 1 second within 1 s...
I have a table in mnesia and I need to update individual fields in the records in it. According to http://stackoverflow.com/questions/1820996/erlang-mnesia-updating-a-single-field-value-in-a-row if I do something like: update_a(Tab, Key, Value) -> fun() -> [P] = mnesia:wread({Tab, Key}), mnesia:write(Tab, P#rec{a=Value}, write...
I have a problem with DB2 databases that should store unicode characters. The connection is established using JDBC. What do I have to do if I would like to insert a unicode string into the database? INSERT INTO my_table(id, string_field) VALUES(1, N'my unicode string'); or INSERT INTO my_table(id, string_field) VALUES(1, 'my unicod...
Can this be done? In a single application, that manages many projects with SQLite. What I want is to have a different database for each project my app is managing.. so multiple copies of an identically structured database, but with different data in them. I'll be choosing which copy to use base on params on the URI. This is done for 1. ...
In my project I have 2 databases. propel-build-model is already set up to work for 2 databases - http://stackoverflow.com/questions/733224/multiple-databases-support-in-symfony If I make changes to either of the databases, I need the propel-build-schema command to rebuild the schemas for both. I know I can do this manually by amending ...
Is there any way to get SQL Server result in charset different from the native database encoding? I mean something like "set names" which is used by MySQL. ...
I'm using the Neodatis ODB Database in my new system. Everything works fine, but I would like to make a Distributed Database. Does anyone knows how can I make that using Neodatis Database(A Database Master Server and his slaves in different computers)? ...
I am working on an embedment section on my site where users can embed different media from various services, youtube, myspace music, vimeo etc I am trying to work out the best way to store it. Users do not have to embed all of the options and can only embed one of each type (one video for example). Initially I thought just have a table...