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  • What is a good DBMS for archiving?

    - by Thomas.Winsnes
    I've been stuck in a MsSql/MySql world now for a few years, and I've decided to spread my wings a little further. At the moment I'm researching which DBMS is good at things needed when archiving data. Eg. lots of writes and low reads. I've seen the NoSQL crusade, but I have a very RDBMS mindset, so I'm a bit skeptical. Anyone have any suggestions? Or even any pointers to where there are some benchmarks etc for this kind of stuff. Thank you :) Thomas

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  • what is the question for the query?

    - by Kevinniceguy
    Sorry...I mean what question will be for this query? SELECT SUM(price) FROM Room r, Hotel h WHERE r.hotelNo = h.hotelNo and hotelName = 'Paris Hilton' and roomNo NOT IN (SELECT roomNo FROM Booking b, Hotel h WHERE (dateFrom <= CURRENT_DATE AND dateTo >= CURRENT_DATE) AND b.hotelNo = h.hotelNo AND hotelName = 'Paris Hilton');

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  • Java MySQL Query Problem MySQLSyntaxErrorException When Creating a Table

    - by Aqib Mushtaq
    I fairly new to MySQL with Java, but I have executed a few successful INSERT queries however cannot seem to get the CREATE TABLE query to execute without getting the 'MySQLSyntaxErrorException' exception. My code is as follows: import java.sql.*; Statement stmt; Class.forName("com.mysql.jdbc.Driver"); String url = "jdbc:mysql://localhost:3306/mysql"; Connection con = DriverManager.getConnection(url, "root", "password"); stmt = con.createStatement(); String tblSQL = "CREATE TABLE IF NOT EXISTS \'dev\'.\'testTable\' (\n" + " \'id\' int(11) NOT NULL AUTO_INCREMENT,\n" + " \'date\' smallint(6) NOT NULL\n" + ") ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ;"; stmt.executeUpdate(tblSQL); stmt.close(); con.close(); And the error is as follows: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ''dev'.'testTable' ( 'id' int(11) NOT NULL AUTO_INCREMENT, 'date' smallint(6) N' at line 1 I would appreciate it if anyone could spot the mistake in this query, as I've tried executing this within phpMyAdmin and it works as it should. Thanks in advance.

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  • Problem with mysql query to replace a string

    - by alex
    I've used mysql's update replace function before, but even though I think I'm following the same syntax, I can't get this to work. Here's what I'm trying to do: UPDATE contained_widgets SET preference_values = REPLACE(preference_values, '<li><a_href="/enewsletter"><span class="not-tc">eNewsletter</span></a></li>', '<li><a_href="/enewsletter"><span class="not-tc">eNewsletter</span></a></li> <li> <a_href="/projects"><span class="not-tc">Projects</span></a></li>'); Query OK, 0 rows affected (0.00 sec) Rows matched: 77 Changed: 0 Warnings: 0 I don't see what I'm missing. Any help is appreciated. I edited "a " to "a_" because the site thinks I'm posting spam links otherwise.

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  • MySQL Query order by numer of rows?

    - by Clemens
    hi, i have a mysql table for votes. there's am id, a project_id and a vote field (which is 1 if a specific project is voted). now i want to generate a ranking from those entries. is there a way to get the number of votes for each project_id and automatically sort the entries by the number of TRUE votes of a project with a single mysql query? Or do you know a php way? e.g. ID - Project ID - Vote 1 - 2 - 1 2 - 2 - 1 3 - 1 - 1 == Project Nr. 2 has 2 Votes Project Nr. 1 has 1 Vote Thanks in advance!

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  • Version of SQLite used in Android?

    - by Eno
    Reason: Im wondering how to handle schema migrations. The newer SQLite versions support an "ALTER TABLE" SQL command which would save me having to copy data, drop the table, recreate table and re-insert data.

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  • Are there any examples/tutorials of using Spring 3.0 with Cassandra as a backend?

    - by zeroDivisible
    Hello, As I had written in title, I am trying to learn Spring 3.0 (I already know Django, Pylons and few simpler MVC frameworks) and try to use Cassandra as a backend for my web application. Are there any real world examples of doing this? Or maybe some tutorials? I know about the existence of documentation of both technologies, yet I am looking for something "faster" to read and get me rolling.

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  • SQL SERVER - Detecting non-indexed columns but used in WHERE clause

    - by Vadi
    How to detect a column included in WHERE clause but used in indexed? Little Background: Until the time the table has few number of records things will be okay, once it started having millions of records then index should be created for a column which is used in WHERE clauses in stored procs, inline queries etc., Since we have hundreds of stored procs and queries that often gets changed by the devs I wanted to have a automated way of identifying those columns that are used in WHERE clauses but not an index is created. How to do that in SQL SERVER 2008?

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  • using dummy row with NOT NULL to solve DEFAULT NULL

    - by Tony38
    I know having DEFAULT NULLS is not a good practice but I have many optional lookup values which are FK in the system so to solve this issue here is what i am doing: I use NOT NULL for every FK / lookup colunms. I have the first row in every lookup table which is PK id = 1 as a dummy row with just "none" in all the columns. This way I can use NOT NULL in my schema and if needed reference to the none row values PK =1 for FKs which do not have any lookup value. Is this a good design or any other work arounds? EDIT: I have: Neighborhood table Postal table. Every neighborhood has a city, so the FK can be NOT NULL. But not every postal code belongs to a neighborhood. Some do, some don't depending on the country. So if i use NOT NULL for the FK between postal and neighborhood then I will be screwed as there has to be some value entered. So what i am doing in essence is: have a row in every table to be a dummy row just to link the FKs. This way row one in neighborhood table will be: n_id = 1 name =none etc... In postal table I can have: postal_code = 3456A3 FK (city) = Moscow FK (neighborhood_id)=1 as a NOT NULL. If I don't have a dummy row in the neighborhood lookup table then I have to declare FK (neighborhood_id) as a Default null column and store blanks in the table. This is an example but there is a huge number of values which will have blanks then in many tables.

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  • Multi-variable indexes in postgres

    - by Jackson Davis
    Im looking at an application where I will be doing quite a few SELECTs where I am trying to find column_a = x AND column_b = y. Is the correct to create that index that something like the following? CREATE INDEX index_name ON table (column_a, column_b)

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  • Does Ruby on Rails "has_many" array provide data on a "need to know" basis?

    - by Jian Lin
    On Ruby on Rails, say, if the Actor model object is Tom Hanks, and the "has_many" fans is 20,000 Fan objects, then actor.fans gives an Array with 20,000 elements. Probably, the elements are not pre-populated with values? Otherwise, getting each Actor object from the DB can be extremely time consuming. So it is on a "need to know" basis? So does it pull data when I access actor.fans[500], and pull data when I access actor.fans[0]? If it jumps from each record to record, then it won't be able to optimize performance by doing sequential read, which can be faster on the hard disk because those records could be in the nearby sector / platter layer -- for example, if the program touches 2 random elements, then it will be faster just to read those 2 records, but what if it touches all elements in random order, then it may be faster just to read all records in a sequential way, and then process the random elements. But how will RoR know whether I am doing only a few random elements or all elements in random?

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  • How Implement a system to determine if a milestone has been reached

    - by Luc M
    I have a table named stats player_id team_id match_date goal assist` 1 8 2010-01-01 1 1 1 8 2010-01-01 2 0 1 9 2010-01-01 0 5 ... I would like to know when a player reach a milestone (eg 100 goals, 100 assists, 500 goals...) I would like to know also when a team reach a milestone. I want to know which player or team reach 100 goals first, second, third... I thought to use triggers with tables to accumulate the totals. Table player_accumulator (and team_accumulator) table would be player_id total_goals total_assists 1 3 6 team_id total_goals total_assists 8 3 1 9 0 5 Each time a row is inserted in stats table, a trigger will insert/update player_accumulator and team_accumulator tables. This trigger could also verify if player or team has reached a milestone in milestone table containing numbers milestone 100 500 1000 ... A table player_milestone would contains milestone reached by player: player_id stat milestone date 1 goal 100 2013-04-02 1 assist 100 2012-11-19 There is a better way to implements a "milestone" ? There is an easiest way without triggers ? I'm using PostgreSQL

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  • Is copying /var/lib/mysql a good alterntive to mysqldump?

    - by kemp
    Since I'm making a full backup of my entire debian system, I was thinking if having a copy of /var/lib/mysql directory is a viable alternative to dumping tables with mysqldump. are all informations needed contained in that directory? can single tables be imported in another mysql? can there be problems while restoring those files on a (probably slightly) different mysql server version?

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  • Detecting changes between rows with same ID

    - by Noah
    I have a table containing some names and their associated ID, along with a snapshot: snapshot, id, name I need to identify when a name has changed for an id between snapshots. For example, in the following data: 1, 0, 'MOUSE_SPEED' 1, 1, 'MOUSE_POS' 1, 2, 'KEYBOARD_STATE' 2, 0, 'MOUSE_BUTTONS' 2, 1, 'MOUSE_POS' 2, 2, 'KEYBOARD_STATE' ...the meaning of id 0 changed with snapshot 2, but the others remained the same. I'd like to construct a query that (ideally) returns: 1, 0, 'MOUSE_SPEED' 2, 0, 'MOUSE_BUTTONS' I am using PostgreSQL v8.4.2.

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  • Autmatically create table on MySQL server based on date?

    - by Anthony
    Is there an equivalent to cron for MySQL? I have a PHP script that queries a table based on the month and year, like: SELECT * FROM data_2010_1 What I have been doing until now is, every time the script executes it does a query for the table, and if it exists, does the work, if it doesn't it creates the table. I was wondering if I can just set something up on the MySQL server itself that will create the table (based on a default table) at the stroke of midnight on the first of the month. Update Based on the comments I've gotten, I'm thinking this isn't the best way to achieve my goal. So here's two more questions: If I have a table with thousands of rows added monthly, is this potentially a drag on resources? If so, what is the best way to partition this table, since the above is verboten? What are the potential problems with my home-grown method I originally thought up?

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  • PHP won't parse MySQL statements

    - by Hussain
    I just installed Apache 2.2.15/PHP 5.3.2/MySQL 5.1.44 on Windows Vista. Apache is working fine, PHP is functional, and MySQL works on the CLI. However, when I try to access MySQL via PHP, I get an error (Fatal error: Call to undefined function mysql_connect()). extension=php_mysql.dll and extension=php_mbstring.dll are uncommented in the php.ini file, and PHP is in the system path. There is no libmysql.dll in either the top level PHP directory or the ext directory. There's a libmySQL.dll file in the MySQL bin directory (which is also in the system path); I tried renaming it, but that doesn't do anything Also, in case anyone wants to know, I originally installed PHP using the MSI installer, but it was missing some DLLs, so I installed from the zip file. I think I've exhausted all my options. Any help on this problem would be very appreciated. Thanks in advance.

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  • PHP mySQL - replace some string inside string

    - by apis17
    i want to replace ALL comma , into ,<space> in all address table in my mysql table. For example, +----------------+----------------+ | Name | Address | +----------------+----------------+ | Someone name | A1,Street Name | +----------------+----------------+ Into +----------------+----------------+ | Name | Address | +----------------+----------------+ | Someone name | A1, Street Name| +----------------+----------------+ Thanks in advance.

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