Search Results

Search found 27519 results on 1101 pages for 'sql learner'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 695/1101 | < Previous Page | 691 692 693 694 695 696 697 698 699 700 701 702  | Next Page >

  • What is the difference between "data hiding" and "encapsulation"?

    - by Software Engeneering Learner
    I'm reading "Java concurrency in practice" and there is said: "Fortunately, the same object-oriented techniques that help you write well-organized, maintainable classes - such as encapsulation and data hiding -can also help you create thread-safe classes." The problem #1 - I never heard about data hiding and don't know what it is. The problem #2 - I always thought that encapsulation is using private vs public, and is actually the data hiding. Can you please explain what data hiding is and how it differs from encapsulation?

    Read the article

  • Need a Quick Sure Method to Produce a Formatted Explain Plan? This will help!

    - by user702295
    Please use the following on the production machine to get formatted explain plan and sql trace using the SLOW sql (e.g. 'T_COMB_LIST.COMB_ID = 216') or any other value that takes longer: -- Open new session is SQL*Plus */ -- Make sure you are using updated PLAN_TABLE -- This can be done by dropping it and recreate it by running: -- SQL> @?/rdbms/admin/utlxplan.sql) set lines 1000 set pages 1000 spool xplan_1.txt EXPLAIN PLAN FOR <<<<Replace this line with exactly the same query you used above. Force hard parse by modifying the case of a character>>>> @?/rdbms/admin/utlxplp spool off EXIT --Open a second session is SQL*Plus ALTER SESSION SET max_dump_file_size = unlimited; ALTER SESSION SET tracefile_identifier = '10046'; ALTER SESSION SET statistics_level = ALL; ALTER SESSION SET events '10046 trace name context forever, level 12'; <<<<Replace this line with exactly the same query you used above. Force hard parse by modifying the case of a character>>>> select 'verify cursor closed' from dual; ALTER SYSTEM SET EVENTS '10046 trace name context off'; EXIT Make sure spooled file is formatted properly and that the 10046 trace has relevant explain plan in it.  Please Upload both files (10046 trace is generated in udump). Need instructions to find udump?   sqlplus "/ as sysdba" show parameters dump_dest This will show you bdump, cdump and udump locations.

    Read the article

  • Strategies for avoiding SQL in your Controllers... or how many methods should I have in my Models?

    - by Keith Palmer
    So a situation I run into reasonably often is one where my models start to either: Grow into monsters with tons and tons of methods OR Allow you to pass pieces of SQL to them, so that they are flexible enough to not require a million different methods For example, say we have a "widget" model. We start with some basic methods: get($id) insert($record) update($id, $record) delete($id) getList() // get a list of Widgets That's all fine and dandy, but then we need some reporting: listCreatedBetween($start_date, $end_date) listPurchasedBetween($start_date, $end_date) listOfPending() And then the reporting starts to get complex: listPendingCreatedBetween($start_date, $end_date) listForCustomer($customer_id) listPendingCreatedBetweenForCustomer($customer_id, $start_date, $end_date) You can see where this is growing... eventually we have so many specific query requirements that I either need to implement tons and tons of methods, or some sort of "query" object that I can pass to a single -query(query $query) method... ... or just bite the bullet, and start doing something like this: list = MyModel-query(" start_date X AND end_date < Y AND pending = 1 AND customer_id = Z ") There's a certain appeal to just having one method like that instead of 50 million other more specific methods... but it feels "wrong" sometimes to stuff a pile of what's basically SQL into the controller. Is there a "right" way to handle situations like this? Does it seem acceptable to be stuffing queries like that into a generic -query() method? Are there better strategies?

    Read the article

  • StreamInsight V2.0 Released!

    - by Roman Schindlauer
    The StreamInsight Team is proud to announce the release of StreamInsight V2.0! This is the version that ships with SQL 2012, and as such it has been available through Connect to SQL CTP customers already since December. As part of the SQL 2012 launch activities, we are now making V2.0 available to everyone, following our tradition of providing a separate download page. StreamInsight V2.0 includes a number of stability and performance fixes over its predecessor V1.2. Moreover it introduces a dependency on the .NET Framework 4.0, as well as on SQL 2012 license keys. For these reasons, we decided to bump the major version number, even though V2.0 does not add new features or API surface. It can be regarded a stepping stone to the upcoming release 2.1 which will contain significantly new APIs (that will depend on .NET 4.0). Head over here to download StreamInsight V2.0. The updated Books Online can be found here. Update: For instructions on how to make your existing application work against the new bits without recompilation, see here. Regards, The StreamInsight Team

    Read the article

  • Is there any complications or side effects for changing final field access/visibility modifier from private to protected?

    - by Software Engeneering Learner
    I have a private final field in one class and then I want to address that field in a subclass. I want to change field access/visibility modifier from private to protected, so I don't have to call getField() method from subclass and I can instead address that field directly (which is more clear and cohessive). Will there be any side effects or complications if I change private to protected for a final field? UPDATE: from logical point of view, it's obvious that descendant should be able to directly access all predecessor fields, right? But there are certain constraints that are imposed on private final fields by JVM, like 100% initialization guarantee after construction phase(useful for concurrency) and so on. So I would like to know, by changing from private to protected, won't that or any other constraints be compromised?

    Read the article

  • StreamInsight V2.0 Released!

    - by Roman Schindlauer
    The StreamInsight Team is proud to announce the release of StreamInsight V2.0! This is the version that ships with SQL 2012, and as such it has been available through Connect to SQL CTP customers already since December. As part of the SQL 2012 launch activities, we are now making V2.0 available to everyone, following our tradition of providing a separate download page. StreamInsight V2.0 includes a number of stability and performance fixes over its predecessor V1.2. Moreover it introduces a dependency on the .NET Framework 4.0, as well as on SQL 2012 license keys. For these reasons, we decided to bump the major version number, even though V2.0 does not add new features or API surface. It can be regarded a stepping stone to the upcoming release 2.1 which will contain significantly new APIs (that will depend on .NET 4.0). Head over here to download StreamInsight V2.0. The updated Books Online can be found here. Update: For instructions on how to make your existing application work against the new bits without recompilation, see here. Regards, The StreamInsight Team

    Read the article

  • ASP.NET MVC3, WebMatrix, NuGet, SQL Compact 4&ndash;all released&hellip;

    - by Shawn Cicoria
    Along with the release of WebMatrix announced here.. http://blogs.msdn.com/b/webplatform/archive/2011/01/12/webmatrix-shipping-january-13-2011.aspx A slew of dependencies were released as well.  If you download WebMatrix, it will install these dependencies – also via a new release of the Web platform installer (3.0). You get IIS 7.5 Express for hosting the Web Matrix projects as well. And, to top it off – the Microsoft Web Deploy 2.0 tool… The ASP.NET updates include the Visual Studio 2010 tools updates, adding the MVC3 templates, and, under websites, adding a template for ASP.NET Web Site (Razor)

    Read the article

  • QxOrm 1.2.3 vient de sortir, l'ORM pour Qt supporte la compilation statique et de nouveaux déclencheurs SQL

    Bonjour, QxOrm 1.2.3 vient de sortir. Voici les nouveautés de la version 1.2.3 : Nouvelle interface qx::IxPersistable (classe abstraite) pour simplifier la notion de polymorphisme en utilisant la bibliothèque QxOrm ; Pour plus de détails sur cette nouvelle interface, rendez-vous sur la FAQ : 'Comment utiliser l'interface qx::IxPersistable ?' ; Nouvelles méthodes pour l'interface qx::IxCollection pour parcourir les éléments de la liste sans connaitre le type associé ...

    Read the article

  • SQL??“ALL”,????

    - by Todd Bao
    ALL????????????,>ALL?>=ALL?<ALL?<=ALL?=ALL?!=ALL???????????????????WHERE????TRUE?????????“=ALL”?????:select employee_id,last_name,department_id  from hr.employees   where department_id =ALL (select department_id from hr.employees where salary > 16000);EMPLOYEE_ID + LAST_NAME         + DEPARTMENT_ID----------- + ------------------------- + -------------    100 + King            +         90    101 + Kochhar            +         90    102 + De Haan            +         903 rows selected.??????????SALARY??16000????????????????????(???90),???????????????????????,????????????department_id???,????????????,???16000???8000:select employee_id,last_name   from hr.employees   where department_id =ALL (select department_id from hr.employees where salary > 8000);no rows selected????,ALL???????????????????WHERE????TURE,??????,??????salary > 77777:select employee_id,last_name   from hr.employees   where department_id =ALL (select department_id from hr.employees where salary > 77777)/?????????????77777??,??????“where department_id =ALL (???)”??TRUE,?????????????:EMPLOYEE_ID + LAST_NAME----------- + -------------------------    198 + OConnell    199 + Grant    ...   .....    196 + Walsh    197 + Feeney107 rows selected.?????????????>ALL?<ALL?>=ALL?<=ALL?!=ALL??,??????????????,???????“?”??????????????????,?“?”?????????????????????????????:select * from hr.employees where department_id >=ALL (null)/Todd

    Read the article

  • C# and MySQL .NET Connector - Any way of preventing SQL Injection attacks in a generic class?

    - by John M
    My idea is to create some generic classes for Insert/Update/Select via a C# (3.5) Winforms app talking with a MySQL database via MySQL .NET Connector 6.2.2. For example: public void Insert(string strSQL) { if (this.OpenConnection() == true) { MySqlCommand cmd = new MySqlCommand(strSQL, connection); cmd.ExecuteNonQuery(); this.CloseConnection(); } } Then from anywhere in the program I can run a query with/without user input by just passing a SQL query string. Reading around on SO is starting to give me the indication that this may lead to SQL injection attacks (for any user-input values). Is there anyway of scrubbing the inputted strSQL or do I need to go and create individual parameterized queries in every method that needs to do a database function?

    Read the article

  • Recreation of MySQL DB using "mysql mydb < mydb.sql" is really slow when the table has tens of milli

    - by Jian Lin
    It seems that a MySQL database that has a table with tens of millions of records will get a big INSERT INTO statement when the following mysqldump some_db > some_db.sql is done to back up the database. (is it 1 insert statement that handles all the records?) So when reconstructing the DB using mysql some_db < some_db.sql then the CPU is hardly busy (about 1.8% usage by the mysql process... I don't see a mysqld either?) and also the hard disk doesn't seem to be too busy... Last time, the whole restore process took 5 hours. Is there a way to make it faster? Such as, when doing mysqldump, can it break the INSERT statement into shorter ones, so that the mysql doesn't need to parse the line so hard when restoring the DB?

    Read the article

  • "ref" vs "out" keyword errors using the sql-net and C# Sqlite combination for windows phone 7.1

    - by param
    I am getting some "ref" vs "out" keyword errors using the sql-net and C# Sqlite combination for windows phone 7.1. Is this due to a wrong combination of libraries that I am using? App Type: Windows Phone 7.1 Using: 1) sql-net Version 1.0.5, Source Nuget thru Visual Studio 2) C# Sqlite for WP7 (wp7sqlite) ( Community.CSharpSqlite.WP7) Version 0.1.1, Source Nuget thru Visual Studio. The exact error I receive is below **Error 5 The best overloaded method match for Community.CsharpSqlite.Sqlite3.sqlite3_open(string, ref Community.CsharpSqlite.Sqlite3.sqlite3)' has some invalid arguments C:\Dev\Learning\SQLite.cs Line:2492 Column: 29 ** The next error then hints that it is related to the parameter being passed as "out" type instead of "ref" type. Error 6 Argument 2 must be passed with the 'ref' keyword C:\Dev\Learning\SQLite.cs Line: 2492 Column: 64 I can make the compile errors go away by replacing the "out" keyword with the "ref" keyword, but that is likely to lead to other issues. Given that I do not see much complain about this issue - I may be doing something wrong but not able to detect easily. Thanks, Parmeshwar

    Read the article

  • Recreation of DB using "mysql mydb < mydb.sql" is really slow when the table has tens of millions of

    - by Jian Lin
    It seems that a MySQL database that has a table with tens of millions of records will get a big INSERT INTO statement when the following mysqldump some_db > some_db.sql is done to back up the database. (is it 1 insert statement that handles all the records?) So when reconstructing the DB using mysql some_db < some_db.sql then the CPU is hardly busy (about 1.8% usage by the mysql process... I don't see a mysqld either?) and also the hard disk doesn't seem to be too busy... Last time, the whole restore process took 5 hours. Is there a way to make it faster? Such as, when doing mysqldump, can it break the INSERT statement into shorter ones, so that the mysql doesn't need to parse the line so hard when restoring the DB?

    Read the article

  • RPC Fails but passing in SQL Man. Studios works

    - by Justin
    I am calling a stored procedure from a web service in an ASP.Net application. And until a few days ago, all was well. However now when i call it I get an error saying The timeout period elapsed prior to the completion of the operation or the server could not be reached. However when i would run SQL SERVER PROFILER, I could see that the call was getting to the database, but was timing out. I then copied the statement being executed found at the bottom of the Profiler and pasted it into Management Studio and executed it and it finishes in about 7 seconds.. This runs just fine on our production server. It seems to be similar to this question: SELECT DISTINCT not working in .NET application, but works in SQL Mgmt Studio but I see no answer.

    Read the article

  • Does Python Django support custom SQL and denormalized databases with no Foreign Key relationships?

    - by Jay
    I've just started learning Python Django and have a lot of experience building high traffic websites using PHP and MySQL. What worries me so far is Python's overly optimistic approach that you will never need to write custom SQL and that it automatically creates all these Foreign Key relationships in your database. The one thing I've learned in the last few years of building Chess.com is that its impossible to NOT write custom SQL when you're dealing with something like MySQL that frequently needs to be told what indexes it should use (or avoid), and that Foreign Keys are a death sentence. Percona's strongest recommendation was for us to remove all FKs for optimal performance. Is there a way in Django to do this in the models file? create relationships without creating actual DB FKs? Or is there a way to start at the database level, design/create my database, and then have Django reverse engineer the models file?

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 691 692 693 694 695 696 697 698 699 700 701 702  | Next Page >