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  • How would one build a relational database on a key-value store, a-la Berkeley DB's SQL interface?

    - by coleifer
    I've been checking out Berkeley DB and was impressed to find that it supported a SQL interface that is "nearly identical" to SQLite. http://docs.oracle.com/cd/E17076_02/html/bdb-sql/dbsqlbasics.html#identicalusage I'm very curious, at a high-level, how this kind of interface might have been architected. For instance: since values are "transparent", how do you efficiently query and sort by value how are limits and offsets performed efficiently on large result sets how would the keys be structured and serialized for good average-case performance

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  • Different Ways to Restore a SQL Server Database

    This article describes the SQL Server database restore principles for full backups, differential backups and transaction log backups and how to perform the restores to get to a particular point in time. This tip describes SQL Server database restore principles on a database that is using the FULL recovery model. FREE eBook – "45 Database Performance Tips for Developers"Improve your database performance with 45 tips from SQL Server MVPs and industry experts. Get the eBook here.

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  • Does MS Access update the data on the clipboard from a query when the data in the database changes?

    - by leeand00
    I was just debugging a macro in MS Access, and when it hit the breakpoint ran a query and I copied the data from it to the clipboard. Some of the values were null before stepping to the next step, then I ran the next step which ran a query which changed the data I had on the clipboard. I then pasted the data and the values that were null before had been changed by the query...leading to a rather large WTF on my part when I pasted the data. So my question is, does MSAccess update the data on the clipboard when it changes in the database? That's the only explanation I have for what occurred there.

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  • How do you create a SQL query in Excel 2007 with a dynamic date range?

    - by Jordan
    I am trying to create a reporting spreadsheet that can print reports for a given time period. The query below works, but when I try to use a "?" parameter in place of the date, I get an error after selecting a cell containing my date. If I use single quotes ('?') I get a conversion from string to date/time failure, if I don't (?) I get a syntax error near @p1. Eventually I will need either a start and end date or a formula adding a month or shift to the starting date/time to filter the data down to important information. The query was built in Microsoft Query. SELECT FloatTable.DateAndTime, TagTable.TagName FROM master.dbo.FloatTable FloatTable, master.dbo.TagTable TagTable WHERE FloatTable.TagIndex = TagTable.TagIndex AND ((FloatTable.DateAndTime={ts '2012-06-01 00:00:00'})) Any assistance would be much appreciated. Thanks in advance.

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  • SQL SERVER – Weekly Series – Memory Lane – #033

    - by Pinal Dave
    Here is the list of selected articles of SQLAuthority.com across all these years. Instead of just listing all the articles I have selected a few of my most favorite articles and have listed them here with additional notes below it. Let me know which one of the following is your favorite article from memory lane. 2007 Spatial Database Definition and Research Documents Here is the definition from Wikipedia about spatial database : A spatial database is a database that is optimized to store and query data related to objects in space, including points, lines and polygons. While typical databases can understand various numeric and character types of data, additional functionality needs to be added for databases to process spatial data types. Select Only Date Part From DateTime – Best Practice A very common question which I receive is how to only get Date or Time part from datetime value. In this blog post I explain the same in very simple words. T-SQL Paging Query Technique Comparison (OVER and ROW_NUMBER()) – CTE vs. Derived Table I have received few emails and comments about my post SQL SERVER – T-SQL Paging Query Technique Comparison – SQL 2000 vs SQL 2005. The main question was is this can be done using CTE? Absolutely! What about Performance? It is identical! Please refer above mentioned article for the history of paging. SQL SERVER – Cannot resolve collation conflict for equal to operation One of the very first error I ever encountered in my career was to resolve this conflict. I have blogged about it and I have realized that many others like me who are facing this error. LEN and DATALENGTH of NULL Simple Example Here is the question for you what is the LEN of NULL value? Well it is very easy – just read the blog. Recovery Models and Selection Very simple and easy explanation of the Database Backup Recovery Model and how to select the best option for you. Explanation SQL SERVER Hash Join Hash join gives best performance when two more join tables are joined and at-least one of them have no index or is not sorted. It is also expected that smaller of the either of table can be read in memory completely (though not necessary). Easy Sequence of SELECT FROM JOIN WHERE GROUP BY HAVING ORDER BY SELECT yourcolumns FROM tablenames JOIN tablenames WHERE condition GROUP BY yourcolumns HAVING aggregatecolumn condition ORDER BY yourcolumns NorthWind Database or AdventureWorks Database – Samples Databases In this blog post we learn how to install Northwind database. I also shared the source where one can download this database as that is used in many examples on MSDN help files. sp_HelpText for sp_HelpText – Puzzle A simple quick puzzle – do you know the answer of it? If not, go ahead and read the blog. 2008 SQL SERVER – 2008 – Step By Step Installation Guide With Images When SQL Server 2008 was newly introduced lots of people had no clue how to install SQL Server 2008 and the amount of the question which I used to receive were so much. I wrote this blog post with the spirit that this will help all the newbies to install SQL Server 2008 with the help of images. Still today this blog post has been bible for all of the people who are confused with SQL Server installation. Inline Variable Assignment I loved this feature. I have always wanted this feature to be present in SQL Server. The last time when I met developers from Microsoft SQL Server, I had talked about this feature. I think this feature saves some time but make the code more readable. Introduction to Policy Management – Enforcing Rules on SQL Server If our company policy is to create all the Stored Procedure with prefix ‘usp’ that developers should be just prevented to create Stored Procedure with any other prefix. Let us see a small tutorial how to create conditions and policy which will prevent any future SP to be created with any other prefix. 2009 Performance Counters from System Views – By Kevin Mckenna Many of you are not aware of this fact that access to performance information is readily available in SQL Server and that too without querying performance counters using a custom application or via perfmon. Till now, this fact has remained undisclosed but through this post I would like to explain you can easily access SQL Server performance counter information. Without putting much effort you will come across the system viewsys.dm_os_performance_counters. As the name suggests, this provides you easy access to the SQL Server performance counter information that is passed on to perfmon, but you can get at it via tsql. Customize Toolbar – Remove Debug Button from Toolbar I was fond of SQL Server Debugger feature in SQL Server 2000. To my utter disappointment, this feature was withdrawn from SQL Server 2005. The button of the debugger is similar to a play button and is used to run debugging commands of Visual Studio. Because of this reason, it gets very much infuriating for developers when they are developing on both – Visual Studio and SSMS. Let us now see how we can remove debugging button from SQL Server Management Studio. Effect of Normalization on Index and Performance A very interesting conversation which started from twitter. If you want to read one link this is the link I encourage you to read it. SSMS Feature – Multi-server Queries Using SQL Server Management Studio (SSMS) DBAs can now query multiple servers from one window. It is quite common for DBAs with large amount of servers to maintain and gather information from multiple SQL Servers and create report. This feature is a blessing for the DBAs, as they can now assemble all the information instantaneously without going anywhere. Query Optimizer Hint ROBUST PLAN – Question to You “ROBUST PLAN” is a kind of query hint which works quite differently than other hints. It does not improve join or force any indexes to use; it just makes sure that a query does not crash due to over the limit size of row. Let me elaborate upon it in the blog post. 2010 Do you really know the difference between various date functions available in SQL Server 2012? Here is a three part story where we explored the same with examples: Fastest Way to Restore the Database Difference Between DATETIME and DATETIME2 Difference Between DATETIME and DATETIME2 – WITH GETDATE Shrinking NDF and MDF Files – Readers’ Opinion Shrinking Database always creates performance degradation and increases fragmentation in the database. I suggest that you keep that in mind before you start reading the following comment. If you are going to say Shrinking Database is bad and evil, here I am saying it first and loud. Now, the comment of Imran is written while keeping in mind only the process showing how the Shrinking Database Operation works. Imran has already explained his understanding and requests further explanation. I have removed the Best Practices section from Imran’s comments, as there are a few corrections. 2011 Solution – Puzzle – SELECT * vs SELECT COUNT(*) This is very interesting question and I am very confident that not every one knows the answer to this question. Let me ask you again – Which will be faster SELECT* or SELECT COUNT (*) or do you think this is apples and oranges comparison. 2012 Service Broker and CAP_CPU_PERCENT – Limiting SQL Server Instances to CPU Usage In SQL Server 2012 there are a few enhancements with regards to SQL Server Resource Governor. One of the enhancement is how the resources are allocated. Let me explain you with examples. Let us understand the entire discussion with the help of three different examples. Finding Size of a Columnstore Index Using DMVs One of the very common question I often see is need of the list of columnstore index along with their size and corresponding table name. I quickly re-wrote a script using DMVs sys.indexes and sys.dm_db_partition_stats. This script gives the size of the columnstore index on disk only. I am sure there will be advanced script to retrieve details related to components associated with the columnstore index. However, I believe following script is sufficient to start getting an idea of columnstore index size. Developer Training Resources and Summary Roundup Developer Training - Importance and Significance - Part 1 In this part we discussed the importance of training in the real world. The most important and valuable resource any company is its employee. Employees who have been well-trained will be better at their jobs and produce a better product.  An employee who is well trained obviously knows more about their job and all the technical aspects. I have a very high opinion about training employees and it is the most important task. Developer Training – Employee Morals and Ethics – Part 2 In this part we discussed the most crucial components of training. Often employees are expecting the company to pay for their training and the company expresses no interest in training the employee. Quite often training expenses are the real issue for both the employee and employer. Developer Training – Difficult Questions and Alternative Perspective - Part 3 This part was the most difficult to write as I tried to address a few difficult questions and answers. Training is such a sensitive issue that many developers when not receiving chance for training think about leaving the organization. Developer Training – Various Options for Developer Training – Part 4 In this part I tried to explore a few methods and options for training. The generic feedback I received on this blog post was short and I should have explored each of the subject of the training in details. I believe there are two big buckets of training 1) Instructor Lead Training and 2) Self Lead Training. Developer Training – A Conclusive Summary- Part 5 There is no better motivation than a personal desire to learn new technology. Honestly there is nothing more personal learning. That “change is the only constant” and “adapt & overcome” are the essential lessons of life. One cannot stop the learning and resist the change. In the IT industry “ego of knowing all” and the “resistance to change” are the most challenging issues. A Quick Look at Logging and Ideas around Logging Question: What is the first thing comes to your mind when you hear the word “Logging”? Strange enough I got a different answer every single time. Let me just list what answer I got from my friends. Let us go over them one by one. Beginning Performance Tuning with SQL Server Execution Plan Solution of Puzzle – Swap Value of Column Without Case Statement Earlier this week I asked a question where I asked how to Swap Values of the column without using CASE Statement. Read here: SQL SERVER – A Puzzle – Swap Value of Column Without Case Statement. I have proposed 3 different solutions in the blog posts itself. I had requested the help of the community to come up with alternate solutions and honestly I am stunned and amazed by the qualified entries. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Memory Lane, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • What is the best way to build a database from a MS Word document?

    - by Jayron Soares
    Please advise me on how to approach this problem: I have a sequential list of metadata in a document in MS Word. The basic idea is to create a Python algorithm to iterate over the information, retrieving just the name of the PROCESS, when is made a queue, from a database. Example metadata: Process: Process Walker (1965) Exact reference: Walker Process Equipment., Inc. v. Food Machinery Corp. Link: http://caselaw.lp.findlaw.com/scripts/getcase.pl?court=US&vol=382&invol= Type of procedure: Certiorari to the United States Court of Appeals for the Seventh Circuit. Parties: Walker Process Equipment, Inc. Sector: Systems is ... Start Date: October 12-13 Arguedas, 1965 Summary: Food Machinery Company has initiated a process to stop or slow the entry of competitors through the use of a patent obtained by fraud. The case concerned a patent on "knee action swing diffusers" used in aeration equipment for sewage treatment systems, and the question was whether "the maintenance and enforcement of a patent obtained by fraud before the patent office" may be a basis for antitrust punishment. Report of the evolution process: petitioner, in answer to respond... Importance: a) First case which established an analysis for the diagnosis of dispute… There are about 200 pages containing the information above. I have in mind the idea of implementing an algorithm in Python to be able to break this information sequence and try to store it in a web database (an open source application that I’m looking for) in order to allow for free consultations.

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  • Does anyone have database, programming language/framework suggestions for a GUI point of sale system

    - by Jason Down
    Our company has a point of sale system with many extras, such as ordering and receiving functionality, sales and order history etc. Our main issue is that the system was not designed properly from the ground up, so it takes too long to make fixes and handle requests from our customers. Also, the current technology we are using (Progress database, Progress 4GL for the language) incurs quite a bit of licensing expenses on our customers due to mutli-user license fees for database connections etc. After a lot of discussion it is looking like we will probably start over from scratch (while maintaining the current product at least for the time being). We are looking for a couple of things: Create the system with a nice GUI front end (it is currently CHUI and the application was not built in a way that allows us to redesign the front end... no layering or separation of business logic and gui...shudder). Create the system with the ability to modularize different functionality so the product doesn't have to include all features. This would keep the cost down for our current customers that want basic functionality and a lower price tag. The bells and whistles would be available for those that would want them. Use proper design patterns to make the product easy to add or change any part at any time (i.e. change the database or change the front end without needing to rewrite the application or most of it). This is a problem today because the Progress 4GL code is directly compiled against the database. Small changes in the database requires lots of code recompiling. Our new system will be Linux based, with a possibility of a client application providing functionality from one or more windows boxes. So what I'm looking for is any suggestions on which database and/or framework or programming language(s) someone might recommend for this sort of product. Anyone that has experience in this field might be able to point us in the right direction or even have some ideas of what to avoid. We have considered .NET and SQL Express (we don't need an enterprise level DB), but that would limit us to windows (as far as I know anyway). I have heard of Mono for writing .NET code in a Linux environment, but I don't know much about it yet. We've also considered a Java and MySql based implementation. To summarize we are looking to do the following: Keep licensing costs down on the technology we will use to develop the product (Oracle, yikes! MySQL, nice.) Deliver a solution that is easily maintainable and supportable. A solution that has a component capable of running on "old" hardware through a CHUI front end. (some of our customers have 40+ terminals which would be a ton of cash in order to convert over to a PC). Suggestions would be appreciated. Thanks [UPDATE] I should note that we are currently performing a total cost analysis. This question is intended to give us a couple of "educated" options to look into to include in or analysis. Anyone who could share experiences/suggestions about client/server setups would be appreciated (not just those who have experience with point of sale systems... that would just be a bonus).

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  • How to install Oracle Database 11g Express Edition on Ubuntu 12.10?

    - by Praneeth Pj
    I installed the Oracle database following the steps mentioned in this blog. Downloaded 11g express edition Created a new user oracle under the group dba. Following steps are executed using this. Unzipped oracle-xe-11.2.0-1.0.x86_64.rpm.zip and then converted the rpm to the Ubuntu package by running: sudo alien --scripts -d oracle-xe-11.2.0-1.0.x86_64.rpm Created /sbin/chkconfig file and added the entries as specified there. Created /etc/sysctl.d/60-oracle.conf and added the entries as specified in the same link as above. Running the commands: ln -s /usr/bin/awk /bin/awk mkdir /var/lock/subsys touch /var/lock/subsys/listener .deb generated in step 3: sudo dpkg --install oracle-xe_11.2.0-2_amd64.deb Left the default values as it is: sudo /etc/init.d/oracle-xe configure Set the following env variables in ~/.bashrc file: export ORACLE_HOME=/u01/app/oracle/product/11.2.0/xe export ORACLE_SID=XE export NLS_LANG=`$ORACLE_HOME/bin/nls_lang.sh` export ORACLE_BASE=/u01/app/oracle export LD_LIBRARY_PATH=$ORACLE_HOME/lib:$LD_LIBRARY_PATH export PATH=$ORACLE_HOME/bin:$PATH Running the commands: chown -R oracle:dba /var/tmp/.oracle chmod -R 755 /var/tmp/.oracle chown -R oracle:dba /tmp/.oracle chmod -R 755 /tmp/.oracle Starting Oracle Database 11g Express Edition instance: sudo service oracle-xe start sqlplus / as sysdba and got the following: SQL*Plus: Release 11.2.0.2.0 Production on Thu Jan 3 09:41:58 2013 Copyright (c) 1982, 2011, Oracle. All rights reserved. Connected to an idle instance. Now when exectuting any SQL statements on SQLplus, I end up with the following error: SQL> select * from dual; select * from dual * ERROR at line 1: ORA-01034: ORACLE not available Process ID: 0 Session ID: 0 Serial number: 0 I have increased the swap memory as specified here $ free -m total used free shared buffers cached Mem: 3901 3428 473 0 182 1988 -/+ buffers/cache: 1258 2643 Swap: 5066 0 5066

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  • How to use function to connect to database and how to work with queries?

    - by Abhilash Shukla
    I am using functions to work with database.. Now the way i have defined the functions are as follows:- /** * Database definations */ define ('db_type', 'MYSQL'); define ('db_host', 'localhost'); define ('db_port', '3306'); define ('db_name', 'database'); define ('db_user', 'root'); define ('db_pass', 'password'); define ('db_table_prefix', ''); /** * Database Connect */ function db_connect($host = db_host, $port = db_port, $username = db_user, $password = db_pass, $database = db_name) { if(!$db = @mysql_connect($host.':'.$port, $username, $password)) { return FALSE; } if((strlen($database) > 0) AND (!@mysql_select_db($database, $db))) { return FALSE; } // set the correct charset encoding mysql_query('SET NAMES \'utf8\''); mysql_query('SET CHARACTER_SET \'utf8\''); return $db; } /** * Database Close */ function db_close($identifier) { return mysql_close($identifier); } /** * Database Query */ function db_query($query, $identifier) { return mysql_query($query, $identifier); } Now i want to know whether it is a good way to do this or not..... Also, while database connect i am using $host = db_host Is it ok? Secondly how i can use these functions, these all code is in my FUNCTIONS.php The Database Definitions and also the Database Connect... will it do the needful for me... Using these functions how will i be able to connect to database and using the query function... how will i able to execute a query? VERY IMPORTANT: How can i make mysql to mysqli, is it can be done by just adding an 'i' to mysql....Like:- @mysql_connect @mysqli_connect

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  • Unable to edit a database row from JSF

    - by user1924104
    Hi guys i have a data table in JSF which displays all of the contents of my database table, it displays it fine, i also have a delete function that can successfully delete from the database fine and updates the data table fine however when i try to update the database i get the error java.lang.IllegalArgumentException: Cannot convert richard.test.User@129d62a7 of type class richard.test.User to long below is the code that i have been using to delete the rows in the database that is working fine : public void delete(long userID) { PreparedStatement ps = null; Connection con = null; if (userID != 0) { try { Class.forName("com.mysql.jdbc.Driver"); con = DriverManager.getConnection("jdbc:mysql://localhost:3306/test", "root", "root"); String sql = "DELETE FROM user1 WHERE userId=" + userID; ps = con.prepareStatement(sql); int i = ps.executeUpdate(); if (i > 0) { System.out.println("Row deleted successfully"); } } catch (Exception e) { e.printStackTrace(); } finally { try { con.close(); ps.close(); } catch (Exception e) { e.printStackTrace(); } } } } i simply wanted to edit the above code so it would update the records instead of deleting them so i edited it to look like : public void editData(long userID) { PreparedStatement ps = null; Connection con = null; if (userID != 0) { try { Class.forName("com.mysql.jdbc.Driver"); con = DriverManager.getConnection("jdbc:mysql://localhost:3306/test", "root", "root"); String sql = "UPDATE user1 set name = '"+name+"', email = '"+ email +"', address = '"+address+"' WHERE userId=" + userID; ps = con.prepareStatement(sql); int i = ps.executeUpdate(); if (i > 0) { System.out.println("Row updated successfully"); } } catch (Exception e) { e.printStackTrace(); } finally { try { con.close(); ps.close(); } catch (Exception e) { e.printStackTrace(); } } } } and the xhmtl is : <p:dataTable id="dataTable" var="u" value="#{userBean.getUserList()}" paginator="true" rows="10" editable="true" paginatorTemplate="{CurrentPageReport} {FirstPageLink} {PreviousPageLink} {PageLinks} {NextPageLink} {LastPageLink} {RowsPerPageDropdown}" rowsPerPageTemplate="5,10,15"> <p:column> <f:facet name="header"> User ID </f:facet> #{u.userID} </p:column> <p:column> <f:facet name="header"> Name </f:facet> #{u.name} </p:column> <p:column> <f:facet name="header"> Email </f:facet> #{u.email} </p:column> <p:column> <f:facet name="header"> Address </f:facet> #{u.address} </p:column> <p:column> <f:facet name="header"> Created Date </f:facet> #{u.created_date} </p:column> <p:column> <f:facet name="header"> Delete </f:facet> <h:commandButton value="Delete" action="#{user.delete(u.userID)}" /> </p:column> <p:column> <f:facet name="header"> Delete </f:facet> <h:commandButton value="Edit" action="#{user.editData(u)}" /> </p:column> currently when you press the edit button it will only update it with the same values as i haven't yet managed to get the datatable to be editable with the database, i have seen a few examples with an array list where the data table gets its values from but never a database so if you have any advice on this too it would be great thanks

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  • Should I use a config file or database for storing business rules?

    - by foiseworth
    I have recently been reading The Pragmatic Programmer which states that: Details mess up our pristine code—especially if they change frequently. Every time we have to go in and change the code to accommodate some change in business logic, or in the law, or in management's personal tastes of the day, we run the risk of breaking the system—of introducing a new bug. Hunt, Andrew; Thomas, David (1999-10-20). The Pragmatic Programmer: From Journeyman to Master (Kindle Locations 2651-2653). Pearson Education (USA). Kindle Edition. I am currently programming a web app that has some models that have properties that can only be from a set of values, e.g. (not actual example as the web app data confidential): light-type = sphere / cube / cylinder The light type can only be the above three values but according to TPP I should always code as if they could change and place their values in a config file. As there are several incidents of this throughout the app, my question is: Should I store possibly values like these in: a config file: 'light-types' = array(sphere, cube, cylinder), 'other-type' = value, 'etc = etc-value a single table in a database with one line for each config item a database with a table for each config item (e.g. table: light_types; columns: id, name) some other way? Many thanks for any assistance / expertise offered.

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  • How do I develop database-utilizing application in an agile/test-driven-development way?

    - by user39019
    I want to add databases (traditional client/server RDBMS's like Mysql/Postgresql as opposed to NoSQL, or embedded databases) to my toolbox as a developer. I've been using SQLite for simpler projects with only 1 client, but now I want to do more complicated things (ie, db-backed web development). I usually like following agile and/or test-driven-development principles. I generally code in Perl or Python. Questions: How do I test my code such that each run of the test suite starts with a 'pristine' state? Do I run a separate instance of the database server every test? Do I use a temporary database? How do I design my tables/schema so that it is flexible with respect to changing requirements? Do I start with an ORM for my language? Or do I stick to manually coding SQL? One thing I don't find appealing is having to change more than one thing (say, the CREATE TABLE statement and associated crud statements) for one change, b/c that's error prone. On the other hand, I expect ORM's to be a low slower and harder to debug than raw SQL. What is the general strategy for migrating data between one version of the program and a newer one? Do I carefully write ALTER TABLE statements between each version, or do I dump the data and import fresh in the new version?

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  • Keeping files or database records? Java and Python

    - by danpalmer
    My website will use a Neural Network to predict thing based on user data. The user can select the data to be used in training the network and then use their trained network to predict things. I am using a framework to create, train and query the networks. This uses Java. The framework has persistence for saving a network to an XML file. What is the best way to store these files? I can see several potential ideas, but I need help on choosing which is best: Save each network to a separate XML file with a name that is stored in the database. Load this each time. Save all the networks to the same XML file with each network having a different name that is stored in the database. Somehow pass what would normally be written to an XML file to the Django site for writing to the database. This would need to be returned to the Java code when a prediction needs to be made. I am able to do 1 or 2, but I think their performance will be quite limited and I am on shared hosting at the moment, so I don't know how pleased they would be with thousands of files. Also, after adding a few thousand records to one XML file, I was noticing a massive performance hit on saving to it. If I were able to implement version 3 somehow I think it would be best. No issues with separate processes accessing the database and I think performance would be better. Not to mention having no files lying around. However, the stuff in the neural network framework I am using (Encog) for saving to a file needs access to a Java file object, not a string that could be saved to a database. Unless there is some Java magic I can do here (I know very little Java), the only way I can see of doing this would be with a temporary files but I don't know if this is the correct way to do it. I would appreciate any ideas on the best way to implement any of the above 3 ideas or any alternatives. Thanks!

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  • how to evaluate query by DMBS?

    - by Kevinniceguy
    How do we evaluate the below database query by DBMS? the query is something like : 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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  • Oracle join query

    - by Jasim
    There are three tables in my db ITEM_MASTER, PRICE_MASTER, COMP_MASTER ITEM_MASTER STORE_CODE ITEM_CODE ITEM_DESC 011 914004 desccc PRICE_MASTER STORE_CODE ITEM_CODE COMP_CODE 011 914004 01 011 914004 02 011 914004 03 011 914004 04 COMP_MASTER COMP_CODE COMP_DESC STORE_CODE 01 comp1 011 02 comp2 011 03 comp3 011 04 comp4 011 I want to get all these for an ITEM_CODE in single query STORE_CODE ITEM_CODE ITEM_DESC COMP_DESC1 COMP_DESC2 COMP_DESC3 COMP_DESC4 011 914004 desccc comp1 comp2 comp3 comp4 How can i write a oracle SQL query for this??

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  • Advantage Database Server: in-memory queries.

    - by ie
    As far as I know, ADS v.10 tries to keep result of query in memory until it is a quite huge. The same should be true for the __output table and for temporary tables. When the result becoming large, swapping stated. The question is what memory limit is set for a query, a worker, whatever? Could this limit be configured? Thanks.

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  • Can I query inside a SQLite Transaction?

    - by CSharperWithJava
    I'm using the SQLite3 database system in the Android library. I need to execute a query during a transaction to see if there is a similar entry already there. If there is, I have to perform some other logic and adjustments before I add a new row. Can I execute a query within a transaction and get the result back immediately?

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  • Issues querying Access '07 database in C#

    - by Kye
    I'm doing a .NET unit as part of my studies. I've only just started, with a lecturer that as kinda failed to give me the most solid foundation with .NET, so excuse the noobishness. I'm making a pretty simple and generic database-driven application. I'm using C# and I'm accessing a Microsoft Access 2007 database. I've put the database-ish stuff in its own class with the methods just spitting out OleDbDataAdapters that I use for committing. I feed any methods which preform a query a DataSet object from the main program, which is where I'm keeping the data (multiple tables in the db). I've made a very generic private method that I use to perform SQL SELECT queries and have some public methods wrapping that method to get products, orders.etc (it's a generic retail database). The generic method uses a separate Connect method to actually make the connection, and it is as follows: private static OleDbConnection Connect() { OleDbConnection conn = new OleDbConnection( @"Provider=Microsoft.ACE.OLEDB.12.0; Data Source=C:\Temp\db.accdb"); return conn; } The generic method is as follows: private static OleDbDataAdapter GenericSelectQuery( DataSet ds, string namedTable, String selectString) { OleDbCommand oleCommand = new OleDbCommand(); OleDbConnection conn = Connect(); oleCommand.CommandText = selectString; oleCommand.Connection = conn; oleCommand.CommandType = CommandType.Text; OleDbDataAdapter adapter = new OleDbDataAdapter(); adapter.SelectCommand = oleCommand; adapter.MissingSchemaAction = MissingSchemaAction.AddWithKey; adapter.Fill(ds, namedTable); return adapter; } The wrapper methods just pass along the DataSet that they received from the main program, the namedtable string is the name of the table in the dataset, and you pass in the query you wish to make. It doesn't matter which query I give it (even something simple like SELECT * FROM TableName) I still get thrown an OleDbException, stating that there was en error with the FROM clause of the query. I've just resorted to building the queries with Access, but there's still no use. Obviously there's something wrong with my code, which wouldn't actually surprise me. Here are some wrapper methods I'm using. public static OleDbDataAdapter GetOrderLines(DataSet ds) { OleDbDataAdapter adapter = GenericSelectQuery( ds, "orderlines", "SELECT OrderLine.* FROM OrderLine;"); return adapter; } They all look the same, it's just the SQL that changes.

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  • Mysql query question

    - by brux
    I have 2 tables: Customer: customerid - int, pri-key,auto fname - varchar sname -varchar housenum - varchar street -varchar Items: itemid - int,pri-key,auto type - varchar collectiondate - date releasedate - date customerid - int I need a query which will get me all items that have a releasedate 3 days prior to (and including) the current date. i.e The query should return customerid,fname,sname,street,housenum,type,releasedate for all items which have releasedate within (and including)3 days prior today thanks in advance

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  • Simple check for SELECT query empty result

    - by den-javamaniac
    Hi. Can anyone point out how to check if a select query returns non empty result set? For example I have next query: SELECT * FROM service s WHERE s.service_id = ?; Should I do something like next: ISNULL(SELECT * FROM service s WHERE s.service_id = ?) to test if result set is not empty?

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  • Simple question on database query.

    - by GK
    I have been asked in an interview, To write a sql query which fetches the first three records with highest value on some column from a table. i had written a query which fetched all the records with highest value, but didnt get how exactly i can get only first three records of those. could you help me in this. thanks.

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  • Check mysql_query results if DELETE query worked?

    - by Camran
    I have a DELETE query which deletes a record from a mysql db. is there any way to make sure if the delete was performed or not? I mean, for a query to FIND stuff you do $res=mysql_query($var); $nr=mysql_num_rows($res); and you get nr of rows returned. Is there any similiar method for deletion of records? Thanks

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  • SQL SERVER – Weekly Series – Memory Lane – #050

    - by Pinal Dave
    Here is the list of selected articles of SQLAuthority.com across all these years. Instead of just listing all the articles I have selected a few of my most favorite articles and have listed them here with additional notes below it. Let me know which one of the following is your favorite article from memory lane. 2007 Executing Remote Stored Procedure – Calling Stored Procedure on Linked Server In this example we see two different methods of how to call Stored Procedures remotely.  Connection Property of SQL Server Management Studio SSMS A very simple example of the how to build connection properties for SQL Server with the help of SSMS. Sample Example of RANKING Functions – ROW_NUMBER, RANK, DENSE_RANK, NTILE SQL Server has a total of 4 ranking functions. Ranking functions return a ranking value for each row in a partition. All the ranking functions are non-deterministic. T-SQL Script to Add Clustered Primary Key Jr. DBA asked me three times in a day, how to create Clustered Primary Key. I gave him following sample example. That was the last time he asked “How to create Clustered Primary Key to table?” 2008 2008 – TRIM() Function – User Defined Function SQL Server does not have functions which can trim leading or trailing spaces of any string at the same time. SQL does have LTRIM() and RTRIM() which can trim leading and trailing spaces respectively. SQL Server 2008 also does not have TRIM() function. User can easily use LTRIM() and RTRIM() together and simulate TRIM() functionality. http://www.youtube.com/watch?v=1-hhApy6MHM 2009 Earlier I have written two different articles on the subject Remove Bookmark Lookup. This article is as part 3 of original article. Please read the first two articles here before continuing reading this article. Query Optimization – Remove Bookmark Lookup – Remove RID Lookup – Remove Key Lookup Query Optimization – Remove Bookmark Lookup – Remove RID Lookup – Remove Key Lookup – Part 2 Query Optimization – Remove Bookmark Lookup – Remove RID Lookup – Remove Key Lookup – Part 3 Interesting Observation – Query Hint – FORCE ORDER SQL Server never stops to amaze me. As regular readers of this blog already know that besides conducting corporate training, I work on large-scale projects on query optimizations and server tuning projects. In one of the recent projects, I have noticed that a Junior Database Developer used the query hint Force Order; when I asked for details, I found out that the basic concept was not properly understood by him. Queries Waiting for Memory Allocation to Execute In one of the recent projects, I was asked to create a report of queries that are waiting for memory allocation. The reason was that we were doubtful regarding whether the memory was sufficient for the application. The following query can be useful in similar cases. Queries that do not have to wait on a memory grant will not appear in the result set of following query. 2010 Quickest Way to Identify Blocking Query and Resolution – Dirty Solution As the title suggests, this is quite a dirty solution; it’s not as elegant as you expect. However, it works totally fine. Simple Explanation of Data Type Precedence While I was working on creating a question for SQL SERVER – SQL Quiz – The View, The Table and The Clustered Index Confusion, I had actually created yet another question along with this question. However, I felt that the one which is posted on the SQL Quiz is much better than this one because what makes that more challenging question is that it has a multiple answer. Encrypted Stored Procedure and Activity Monitor I recently had received questionable if any stored procedure is encrypted can we see its definition in Activity Monitor.Answer is - No. Let us do a quick test. Let us create following Stored Procedure and then launch the Activity Monitor and check the text. Indexed View always Use Index on Table A single table can have maximum 249 non clustered indexes and 1 clustered index. In SQL Server 2008, a single table can have maximum 999 non clustered indexes and 1 clustered index. It is widely believed that a table can have only 1 clustered index, and this belief is true. I have some questions for all of you. Let us assume that I am creating view from the table itself and then create a clustered index on it. In my view, I am selecting the complete table itself. 2011 Detecting Database Case Sensitive Property using fn_helpcollations() I received a question on how to determine the case sensitivity of the database. The quick answer to this is to identify the collation of the database and check the properties of the collation. I have previously written how one can identify database collation. Once you have figured out the collation of the database, you can put that in the WHERE condition of the following T-SQL and then check the case sensitivity from the description. Server Side Paging in SQL Server CE (Compact Edition) SQL Server Denali is coming up with new T-SQL of Paging. I have written about the same earlier.SQL SERVER – Server Side Paging in SQL Server Denali – A Better Alternative,  SQL SERVER – Server Side Paging in SQL Server Denali Performance Comparison, SQL SERVER – Server Side Paging in SQL Server Denali – Part2 What is very interesting is that SQL Server CE 4.0 have the same feature introduced. Here is the quick example of the same. To run the script in the example, you will have to do installWebmatrix 4.0 and download sample database. Once done you can run following script. Why I am Going to Attend PASS Summit Unite 2011 The four-day event will be marked by a lot of learning, sharing, and networking, which will help me increase both my knowledge and contacts. Every year, PASS Summit provides me a golden opportunity to build my network as well as to identify and meet potential customers or employees. 2012 Manage Help Settings – CTRL + ALT + F1 This is very interesting read as my daughter once accidently came across a screen in SQL Server Management Studio. It took me 2-3 minutes to figure out how she has created the same screen. Recover the Accidentally Renamed Table “I accidentally renamed table in my SSMS. I was scrolling very fast and I made mistakes. It was either because I double clicked or clicked on F2 (shortcut key for renaming). However, I have made the mistake and now I have no idea how to fix this. If you have renamed the table, I think you pretty much is out of luck. Here are few things which you can do which can give you an idea about what your table name can be if you are lucky. Identify Numbers of Non Clustered Index on Tables for Entire Database Here is the script which will give you numbers of non clustered indexes on any table in entire database. Identify Most Resource Intensive Queries – SQL in Sixty Seconds #029 – Video Here is the complete complete script which I have used in the SQL in Sixty Seconds Video. Thanks Harsh for important Tip in the comment. http://www.youtube.com/watch?v=3kDHC_Tjrns Advanced Data Quality Services with Melissa Data – Azure Data Market For the purposes of the review, I used a database I had in an Excel spreadsheet with name and address information. Upon a cursory inspection, there are miscellaneous problems with these records; some addresses are missing ZIP codes, others missing a city, and some records are slightly misspelled or have unparsed suites. With DQS, I can easily add a knowledge base to help standardize my values, such as for state abbreviations. But how do I know that my address is correct? Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Memory Lane, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • ???????:“Upgrade to Oracle Database 12c”

    - by hamsun
    ? ?:Brandye Barrington,2014?4?29? ??????????????“Upgrade to Oracle Database 12c”,??Oracle????(OCM ) ??????????Gwen Lazenby??????12??????????43?????,Gwen Lazenby? ?????Oracle???? 1Z0-060???????????, ? ?????????????????????,????????? ???????????????,? ?????? ?????????:Upgrade to Oracle Database 12c? ??????????????????????????Kaplan SelfTest? ???? ??????? ????:Upgrade to Oracle Database 12c, ???? ?????????:Upgrade to Oracle Database 12c? ?????????????????????????????Kaplan SelfTest? ???? ? ?????????????: ??0:???? ?? 1:?????????????? ?? 2:?????CDB?PDB ?? 3: ??CDB?PDB ?? 4:???????????????????????(?CDB/PDB? ?? 5:?CDB/PDB????????? ? ?? 6:??????????? ?? 7:??Unicode?EM Express? ???? ?? 8:????????????? ?? 9:????????????? ?? 10: ?? ?? 11:????????? ?? 12: ?? ?? 13:?????????????? ?? 14: Oracle Database 12c??RMAN? ??? ?? 15: ??????? ?? 16:ADR???? ?? 17:Oracle Database 12c?????? ?? 18:?? Oracle? ???? ?? 19: ??Oracle Database 12c  ?? 20:??Oracle? ??? ?? 21: ??????? ?? 22: ???? ?? 23: ???? ?? 24: ?????? ?? 25: ?????? ?? 26: ?? ?? 27: ?? ?? 28: ??????? ?? 29: ? ??????????? ?? 30: ??????? ?? 31: ?????? ?? 32: ???????? ?? 33:??RMAN? ???????? ?? 34: ??RMAN???? ?? 35: ???? ?? 36: ?????? ?? 37: ?????? ?? 38: ???????? ?? 39: ???? ?? 40: ?????? ?? 41:??SQL ? ?????? ?? 42:?????Direct NFS ?? 43:??Oracle Data Pump? ??? ????????Oracle Database Administrator Certified Professional?????Oracle Database 12c,????????????????,???????????,????????????????,?????????? ????,?????????????????? ? ??? ?????: Certification Exam Prep Seminar: Upgrade to Oracle Database 12c ??????????: Exam Prep Seminar Value Package: Upgrade to Oracle Database 12c ????: 1Z0-060 Upgrade to 12c - New Features of Oracle Database 12c ????:Oracle Database 12c Administrator Certified Professional

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