Database Development

Synchronizing Data base with Android application

3 Jan 2013 by WebMaster

I guess you can do by this way: At server-side, you define some web services.At Android application, you define servie that run in background, and invoke to those web servies in a interval you defined before.To invoke web services from Android application, you can use open source lib named...

Using Redis for Storing and Working with Geospatial Data

10 Aug 2022 by Aleksandr Ulanov

Learn how to use Redis and its geospatial indexes and commands for complex geo calculations

Dynamically Add Access Database Columns at Runtime using VB.NET

21 Apr 2013 by Rob Culhane

How to dynamically add access database columns at runtime using VB.NET

Getting Started with PouchDB - Part 1

15 Jan 2019 by Paul D. Sheriff

As more and more users interact with web applications on their mobile devices, it is becoming increasingly important for software developers to allow them to work offline; PouchDB can help.

Introduction to NoSQL and Polyglot Persistence

16 Oct 2017 by Nikola M. Živković

Introduction to NoSQL and Polyglot Persistence

NoSQL

Aggregate Product function extends SQL

19 Feb 2015 by DrABELL

Technique to extend capability of standard SQL by adding the Aggregate Product Function

Get Ready to Learn SQL: 8. Database Normalization Explained in Simple English

22 Oct 2014 by essentialSQL

Database normalization in SQL explained in simple English

normalization

Can Use Xml File As DataBase

16 Apr 2013 by Sergey Alexandrovich Kryukov

If your XML file is small enough to keep all the data in memory, this is a simple easy way to implement a kind of a database; and you would enjoy the huge benefits of purely object-oriented database, no mapping code. If this is not the case, however, such approach would be very awkward, and I...

Indexed Views and How It Can Help in Improving Query Performance

23 Mar 2019 by Minh Tuan Do

A considerable method to speed up query running time

How to Create SQL Server Database Project With Visual Studio

4 Apr 2021 by Rijwan Ansari

Learn about SQL Server Database Project (Template) available in VS

Record Count of Tables in SQL Server

19 Feb 2010 by Md. Marufuzzaman

This is good... You can also consider this link.[^]

SQL-Server-2005

Working with database in C#

7 Jan 2012 by Sergey Alexandrovich Kryukov

I would recommend this simple, clear, short an informative CodeProject article for beginners: Using ADO.NET for beginners[^].—SA

Is it a good idea to start playing with open source projects for beginners?

9 Feb 2014 by Sergey Alexandrovich Kryukov

The question makes no sense at all, because you did not tell anything about the goals of the software you need to have.As you mentioned that you want to "create" software, it sounds like you would need to find open-source software to learn how to do programming (otherwise you would know...

Visual-Studio

Manage Entity Framework Code First in Real Time Projects

28 Jul 2014 by DiponRoy

How to manage Entity Framework Code First in Real Time Projects

Performance testing of ORM layers in Python and C++

27 Jan 2015 by Vaclav Naydenov

Comparing the performance of two similar CRUD server apps, one written in Python and SQLAlchemy, the other in C++ and YB.ORM.

Cross Join Introduction – Create Row Combinations

29 Dec 2016 by essentialSQL

Introduction to cross join - create row combinations

SqlServer & EF7: Using datetime vs datetime2 date type

8 Jun 2023 by Mark Pelf

Showing problems with limited accuracy of SqlServer data type “datetime” in .NET7 EF7 environment

pattern recognition for data partition

26 Jan 2011 by Sergey Alexandrovich Kryukov

This is called "Cluster analysis", your problem is probably the most elementary one.I don't know your chances to find anyone who has some ready-to-use code or algorithm, but you can start with this article, just to get and idea what's...

How to find a specific string from stored procedures, triggers and functions in database

4 Feb 2012 by RasikaLB

You can find queries to find a specific string from MSSQL Server

server

T-SQL reporting engine

20 Jun 2013 by Levente Kupás

If you have big reports which run slowly, you may use this T-SQL based engine to speed-up them.

Full Service SQLite for WPF (Including File Handling)

19 Jun 2015 by ergohack

System.Data.SQLite is great, but was missing some BLOB support. Switching to the native source project was easier than expected and provided significant functionality benefits.

Realm Database Tutorial For Android – Part 1

27 Jun 2016 by Val Okafor

Realm Database Tutorial For Android – Part 1

The delete button is too slow what is the problem

8 Jan 2019 by RickZeeland

Instead of sending lots of commands you could try sending one command using the "IN" clause, see example here: SQL IN Operator[^]

DataGridView

MFC CRecordset - How to Bypass the 255 Column Limit

21 May 2021 by rev78

Simply bypass the 255 columns in MFC CRecordset

4db: A Dynamic File-based NoSQL Database for C++

22 Nov 2021 by Michael Sydney Balloni

Wanna add basic database functionality to your C++ app? Too lazy to use SQLite directly? Read on!

what is the best database for C++

15 Mar 2011 by Sergey Alexandrovich Kryukov

I'm sure the only valid answer would be this: http://en.wikipedia.org/wiki/Comparison_of_database_tools[^].That leaves for your choice from this table, which is entirely defined by your purpose :-)Honestly.—SA

C++

Too many extra fields in Database

25 May 2011 by Manfred Rudolf Bihy

DBMS are relational and so should be your data model.This is what I would do:TABLE_WebPage------------integer id; //primary auto increment keyvarchar(50) name; //maybe UNIQUE index on that onevarchar(300) url;...TABLE_PageMetaTag------------------integer id;...

what would be the datatype of a feild containing fingerprints in sql database?

6 Jul 2012 by OriginalGriff

That's going to depend on what you have them as in your app. If they are images as seems likely, then varbinary(max) would be a good choice. If they need additional info then you might want to store them in two fields to make separating them before use easier.

SQL-Server-2008

how to open a windows form after a login form

18 Aug 2012 by _Amy

Hi,Try adding this when login is successful:if (dr.HasRows == true){ MessageBox.Show("Login Successfull", "Login Information"); this.Hide(); //This will hide your current form MyWinForm1 M1 = new MyWinForm1();//Create the object of your second form ...

Visual-Studio

Get Ready to Learn SQL: 11. Database Third Normal Form Explained in Simple English

3 Nov 2014 by essentialSQL

Database Third Normal Form explained in simple English

normalization

How to Write SQL – Understand Database Table Meanings and Relationships – Step 1

19 Jan 2016 by essentialSQL

How to Write SQL – Understand Database Table Meanings and Relationships – Step 1

A Practical Approach of Time Travel Concept in Business Intelligence Scenarios using Temporal Tables on Data Warehouses

10 Feb 2016 by Jesus Carroll

SQL Server 2016 introduces support for system-versioned temporal tables as a database feature that brings built-in support for providing information about data stored in the table at any point in time rather than only the data that is correct at the current moment in time.

Build a Calendar Without Pre-Existing Tables

31 Jan 2017 by #realJSOP

Using common table expressions to build data from thin air.

Automating the SQL Database Mirroring Setup

30 Dec 2019 by Dathuraj Pasarge

Database mirroring setup without any DBA effort - on every new database creation

union,cartesian product

26 Sep 2010 by Henry Minute

Well, yes and no. :) For example in an employee table that includes a manager attribute, one solution to discovering the hierarchy is to use a self join which can result in a cartesian product.So yes, because there would only be one table. No because it is being treated as two tables for...

C#: Common Database

6 Jan 2011 by OriginalGriff

Yes. Sort of.You would have a ConnectionString which supplies the address and login details for the database, but after that you need to supply code or browser html to access the database itself and enter / extract the records.Note I would suggest that for the DB you look at MsSql or...

LAN

Can't get my data into a SQL Database?

20 Jan 2011 by OriginalGriff

Try:INSERT INTO "table_name" ("column1", "column2", ...) VALUES ("value1", "value2", ...)as your SQL command. By preference, do it using Parameterised queries:cmd = new SqlCommand("INSERT INTO PatientDetails (Name, HeartScore) VALUES (@NAME, @HEARTSCORE)",...

How to select random rows from a SQL Server table

9 Feb 2011 by Espen Harlinn

I think this is what you are looking for:Limiting Result Sets by Using TABLESAMPLE[^]RegardsEspen Harlinn

How to select last two inserted rows

15 Feb 2011 by Sharma Richa

SELECT TOP(2) * FROM [tablename] ORDER BY Id DESCsecond isSELECT TOP(5) * FROM [table] ORDER BY salary DESC

WPF: Changes in datagrid to reflect in database table

24 Mar 2011 by Espen Harlinn

Take a look at:WPF DataGrid Practical Examples[^]RegardsEspen Harlinn

Which Database file to use?

6 Apr 2011 by Dylan Morley

SQL Express 2005 should be fine for what you're trying to achieve. What you need to think about here is how the SQL instance is exposed over the network and how clients are going to connect to it. This is going to be the same issue for any RDBMS you might choose, such as MySql[^]For...

Which Database file to use?

6 Apr 2011 by Wendelius

Hi,The choice depends on many different factors, like:- performance requirements- underlying OS- upgradability- licensing issues (possible existing licenses at client etc)- estimated size in 1,2,5 years- number of (concurrent) users/transactions etcIf you were unable to...

The order of condition expressions in SQL queries?

18 Apr 2011 by OriginalGriff

Do you want the bad news? Sorry, but SQL does not behave the same as C, C++ and C#. In those, AND clauses are always executed left - to right, and any false result will abort the operation (called "evaluation short-circuiting"). SQL does not do that. What it does do is more complex. There is a...

SQL Stored Procedure Question?

19 May 2011 by CS2011

There is no hard and fast rule for this. This depends on many criteria like what is database (i.e Oracle, DB2,Sql server etc ) and what is the operation performed inside the SP(insert/update or just a select). In case of select opration inside SP the SP may execute over multiple threads(this is...

Can anyone see what is wrong with this code?

24 Aug 2011 by Herman<T>.Instance

the value of FoodName in c# is NULL. How is FoodName set when not found in item?read my article about disadvantages of sqlparameters.Disadvantages of SqlParameters Turned into Advantages[^]you need somethind like this:private static void CheckParameters(List...

Is there any advantage of using multiple DB in one application ?

13 Sep 2011 by Mehdi Gholam

The general principal to keep in mind is don't make more work for yourself than is absolutely necessary. Most clients and users don't care about how and where their data is stored unless it is safe and consistent. Rarely to client insist on using a specific type of database engine.In...

Do we need to promote stored procedures anymore?

24 Sep 2011 by Sander Rossel

I partly agree. I do not quite get your "SP's are not faster" point. You make Command Objects with query strings? You pass to them Parameter Objects so you have a parameterized query? If you go at it that way I can imagine there is no speed penalty, since that approach simply executes the query...

stored-procedure

database design and algorithm for Public Transport?

6 Feb 2012 by Espen Harlinn

Have a look at:WPF: A* search[^]It does most of what you actually need. Best regardsEspen Harlinn

algorithm

SQL SELECT statement with text field C# .NET

26 Nov 2013 by Maciej Los

I would suggest you to use Stored procedure instead command text in a code behind.Please, see: Return Data from a Stored Procedure[^]How to: Execute a Stored Procedure that Returns Rows[^] SP should looks like this one:SELECT *FROM [users]WHERE [name]=@usernameBy The Way: Do...

How to Get current time zone in SQL and Oracle

7 May 2014 by Kornfeld Eliyahu Peter

You can use DBTIMEZONE or SESSIONTIMEZONE for that...http://docs.oracle.com/cd/B19306_01/server.102/b14200/functions143.htm[^]http://psoug.org/definition/DBTIMEZONE.htm[^]

Entity Framework Code First Migrations Alternative

30 Jul 2014 by DiponRoy

How to handle database scheme changes with normal SQL scripts, without migration in Entity Framework code first

diff bet. select * and select column name in sql query

4 Sep 2014 by Wendelius

This sounds a bit like a homework....Anyhow, there are quite a few differences. To name some from the top of my head:the amount of columns is differentthe order of the same columns returned may be differentthe second one may fail because of wrongly typed column namethe second one may...

Get Ready to Learn SQL: 10. Database Second Normal Form Explained in Simple English

21 Oct 2014 by essentialSQL

Database Second Normal Form explained in simple English

MEAN web development #7: MongoDB and Mongoose

7 Sep 2015 by Sander Rossel

The seventh in a series on MEAN web development.

Unattended installation of SQL Server 2012

11 Jul 2016 by Jesus Carroll

Despite the references of several sources of unattended installation of Microsoft SQL Server Database Engine, in this article describes a script tested in real production environments and it can be used with minimal or - perhaps - no modifications.

C# comparing and extracting data from 2 list<>

14 Jul 2016 by OriginalGriff

If I do a dummy setup and test on your code:public class MachineAD { public string Name; public int ID; }public class Machine { public string BarCode; }public class MachineUnified { public int IDad; public string NameFromAD; public...

data

Internal .NET framework data provider error 12

17 Nov 2016 by Richard Deeming

As I suspected, you're sharing a single OleDbConnection instance across multiple calls. All of the errors you're describing are caused by multiple threads trying to access that single object at the same time.For example:Thread 1: Gconn = New OleDb.OleDbConnectionThread 1:...

OleDb

Amount to Words

18 Dec 2016 by NightWizzard

Convert amounts to their spoken equivalents

How many coulmns can I create in SQL server database

8 Feb 2017 by #realJSOP

I would create two tables - One with patient identifying information, and the other with all other fields.This will make it easier to satisfy HIPAA requirements later.Table PHI:PatientID (this should be the biggest integer type supported by your...

Can we get result using CROSS APPLY?

24 Feb 2019 by CHill60

It is highly unlikely that you need to use a loop of any kind. My article Processing Loops in SQL Server[^] offers several worked examples with alternatives to loops. In this case you need to identify the individual timeslots that exist on the production table e.g. create table #timeslots (id...

What is the mistake in that code

6 Jul 2019 by MadMyche

There are most likely multiple errors in your statement. The main issue I see is a major vulnerability known as SQL Injection. You should NEVER EVER piece user entered data asstrings together to form a SQL statement. The proper way to add variables into a command is via Parameters string sQry =...

DataProvider - A Static Library for Handling Databases from C++

8 Jan 2022 by Michael Haephrati

A Static Library which can be used for all kinds of database related needs

Four Pitfalls of SQL Processing with NULL Values

1 Nov 2022 by Tomas@PawSQL

How to cope with all scenarios regarding NULL value handling in your daily work

PostgreSQL

How to Deploy Entity Framework Database Migrations

2 Mar 2023 by Lee P Richardson

Deploy EF database migrations while avoiding security flags

security

How do I link two lists together by observable collection in VB.NET ?

17 Mar 2024 by Graeme_Grant

You would use a CollectionViewSource and use grouping. I assume that you are using WPF. Here is a sample: How to: Sort and Group Data Using a View in XAML - WPF .NET Framework | Microsoft Learn[^]. Hereare some more things that you can do with...

Syntax error in UPDATE statement

18 Dec 2009 by Vinayaka Krishna Shenoy

Hello,Ye...

.NET3.5

Store MP3 in database

25 Oct 2010 by Nish Nishant

There are two approaches to take:1) Store the mp3 content directly in the DB. This is probably not a great idea. Most databases will have some kind of blob field type that you can use for this.2) Store file paths to the actual mp3 content, which will remain as physical files on a server.

C#2.0

How to differentiate Records

13 Jan 2011 by Simon_Whale

import the excel data and run an outer join queryAccess Outer join query[^]

sql server in user computer

17 Jan 2011 by OriginalGriff

It depends. Normally, you would install SQL Server in one PC, and the others then connect to it over the network. The clients then need no extra installation unless they are editing teh database directly, rather than via your app.If you are using SQL server as a standalone database that...

How to select random rows from a SQL Server table

9 Feb 2011 by Nish Nishant

See http://stackoverflow.com/questions/848872/select-n-random-rows-from-sql-server-table[^]

nth height salary from database

24 Feb 2011 by Espen Harlinn

CREATE TABLE Employee(Id bigint identity not null primary key,Name nvarchar(255) not null,Salary DECIMAL not null)goINSERT INTO Employee(Name,Salary) VALUES('Emp1',100001)goINSERT INTO Employee(Name,Salary) VALUES('Emp2',100002)goINSERT INTO Employee(Name,Salary)...

Add data to a database using a listbox

10 Mar 2011 by fjdiewornncalwe

For starters, don't try to mix up your logic. Separate what you want to do in your UI from what you want to do in your application logic. What I mean is that you should treat your "Yes" or "No" click logic and what happens on the form separately from the logic that you use to write information...

forms

Using a table column twice as compound foreign key

14 Mar 2011 by Manfred Rudolf Bihy

Of course you can have a table like that! Let's call the relation (table) "DirectAncestors" for example:Table DirectAncestors:PersonId bigint; (Foreign key to table Person.ID)FatherID bigint; (Foreign key to table Person.ID) MotherID bigint; (Foreign key to table Person.ID)The...

Which Database file to use?

6 Apr 2011 by Sergey Alexandrovich Kryukov

You already got an overview of the criteria, see the Answer by Mika.Now, you have something to select from and perform comparison. See http://en.wikipedia.org/wiki/Comparison_of_relational_database_management_systems[^] and...

What is it impossible to formulate complex queries?

7 Apr 2011 by OriginalGriff

It isn't impossible to formulate such queries, but it is very difficult to design a user interface that allows non-technical people to construct them, without scaring off the idiots that will by any old tat on eBay average eBay user.Think about it: Google lets you do some of this, with...

Internet

how can i create a project related to data mining

22 Apr 2011 by Abhinav S

This could [^]help you get started.This[^] might also help.

Reading DB Result sets in object hierarchy

15 May 2011 by Wonde Tadesse

It is not clear how and what framework you used to implement your application. But, if you are comfortable working with ADO Entity Framework[^] or NHibernate[^], such kind of query propagation is really easy. Just explore them.I hope this helps you well.

ASP.NET

using of group by function in sql query

19 May 2011 by walterhevedeich

Put the columns that are not inside an aggregate function in the GROUP BY clause. Like this for example."select email,name,mobile,b.custrefno,SUM(b.paidamount) as paidamount from paym b,addcust a where b.custrefno=a.custrefno GROUP BY b.custrefno,email,name,mobile";

Is it possible to use multi sqldependency?

25 May 2011 by Not Active

Need to add more words because this won't except a simple, yes

Exception databaseSystem.NullReferenceException in c#

8 Jun 2011 by OriginalGriff

Change comm = new OdbcCommand("select * from utilisateur where login=?", cn); comm.Parameters.Add("login", login.Text);To comm = new OdbcCommand("select * from utilisateur where login=@LI", cn); comm.Parameters.Add("@LI",...

exceptions

Exception databaseSystem.NullReferenceException in c#

8 Jun 2011 by Sandeep Mewara

Adding to other answer:" System.NullReferenceException: Object reference not set to an instance of an object."This simply means that you are trying to access a property of an object that is null. Using Visual Studio DEBUGGER will tell you exact line and the object that is null and thus...

exceptions

Read from database error but no error message

1 Aug 2011 by Shameel

You have not mentioned what database it is. If it is SQL Server (as you have used SqlConnection class) then, as digimanus suggested, rewrite your query asSELECT TOP 1 * FROM [User]There is no LIMIT clause in MS SQL Server.If you database is indeed MySQL, then use the appropriate Library...

Read from database error but no error message

1 Aug 2011 by Wonde Tadesse

This probably happens due to LIMIT key word. If you are using SQL Server, it might not support the key word. Take a look at this Channel 9 discussion. SQL Server and LIMIT clauses on SELECT statements[^]

Job scheduler in SqlServer

27 Aug 2011 by Shameel

Write a Stored Procedure that does your work and execute it at regular intervals using SQL Server Job[^].

How do I get This Output in database?

2 Sep 2011 by Wendelius

This looks like a bad design. Instead of having years and values as separate columns, you should use a table with two columns:- Year- ValueSo the data in the table would be:Year Value---- -----2010 1552011 1192012 145With that, you would query for proper year always from...

MySQL

Server - Client Application?

2 Sep 2011 by Abhinav S

StepsStep 1) You need to host the database in central server / location and allow client programs to access it.Step 2) You will need to make sure all clients have network access to this location.Step 3) To do this, you will need to setup a database connection, say an ODBC setup, on every...

Working with database in C#

7 Jan 2012 by uspatel

if you want to create database using C#,see thisCreate a SQL Server Databaseuse ADO.net for database connectivityADO.Netotherwise sql server mgmt. studio is easiest way to create database and tables.see this http://www.sqlserver2005tutorial.com/

i want code for c# for connecting asp.net and sql

14 Jan 2012 by OriginalGriff

Try: using (SqlConnection con = new SqlConnection(strConnect)) { con.Open(); using (SqlCommand com = new SqlCommand("SELECT iD, description FROM myTable", con)) { using (SqlDataReader reader =...

ASP.NET

how to do automatic email sending in asp.net using c# with steps

12 Feb 2012 by Mycroft Holmes

Ah it is the automated issue that is the problem.I would use a SQL server job that runs periodically to check for expired data events and generate the email and send it via SQL mail and SMTP.Either that or use a timer in your c# app to do the same thing.You could also write a service...

Intercepting Database Query Commands

15 Feb 2012 by Ed Nutting

Hi all,I have a Microsoft SQL Server database and I am using LINQ to SQL to interact with it in my ASP.Net C# 4.0 Website. What I would like to do is have a method that before a query is submitted to the database, grabs the command that will be sent and allows me to look at it. Basically, I...

LINQ

DataContext

connect database located in another program

18 Apr 2012 by Mohammad A Rahman

Hope it helps The Connection String Reference[^]:)

connect to database placed in another program

29 Apr 2012 by Espen Harlinn

One place to start is here: WCF Data Services[^]Then there is Introduction to ADO.NET Data Services/RIA Services[^] By Sacha Barber[Update]Try replacing localhost with (local)Data Source=(local)Best regardsEspen Harlinn

connect to database placed in another program

29 Apr 2012 by Sandeep Mewara

Generally, it is surface area configuration error or sql service configuration issue. Have a look at this thread for potential reasons and resolutions: Resolving A network-related or instance-specific error occurred while establishing a connection to SQL Server[^]If needed, See steps for...

sql error 26

7 May 2012 by OriginalGriff

Why are you using an SqlConnection to connect to an SDF file? Why not use an SqlCeConnection?SqlCeConnection connection = new SqlCeConnection();connection.ConnectionString = @"Data Source=D:\NewCode\DataBaseWin.sdf;Integrated Security=SSPI";connection.Open();

run same command for all tables in a databse of sql

15 May 2012 by Mohamed Mitwalli

Hi , Check this using ( SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["testConnectionString"].ConnectionString)) { using(SqlCommand cmd = new SqlCommand("SELECT TABLE_NAME FROM...

Delete All Record From Database

24 May 2012 by Wendelius

Your code looks valid at a glance. When you call the ExecuteNonQuery, take the return value into a variable. So modify your code to...int rowsaffected = command1.ExecuteNonQuery();...Now using debugger, check what is the value of rowsaffected. It should be the total amount of rows.If...

DataTable

Delete All Record From Database

24 May 2012 by Maciej Los

The command DELETE FROM Onlineis correct, but i prefer to use TRUNCATE[^] (see my comment to Mark Nischalke anser).In my opinion, the problem is in the below procedure: private void Form1_FormClosing(Object sender, FormClosingEventArgs e) { StopServer(); ...

DataTable

sql query: make the system to select all where Suppliername is equal to textbox value

15 Jul 2012 by OriginalGriff

As Wes says - it's pretty obvious! But please, please, don't do it that way! Do not concatenate strings to build a SQL command. It leaves you wide open to accidental or deliberate SQL Injection attack which can destroy your entire database. Use Parametrized queries instead: ...

forms

I can't make up my own mind!!!! A LITTLE HELP PLEASE!!

16 Jul 2012 by Albert Holguin

For inventory control, I would definitely go towards an actual database. You said it yourself, it's going to get large fast, so relational databases are the best method of storing, recalling, and searching through large amounts of data. It might complicate things up front but it's definitely...

MFC