What is the connection string? Give some examples?

When your application connects to a database(db) or a data file you let your provider (ADO/ADO.Net) utilize to do the job for you. This connection string contains the info that the provider need to know to be able to establish a connection to the related db or datafile.

 

You can see this C#.Net  example which creates a SQLConnection and set the ConnectionString property before opening the connection:

 

private static void OpenSqlConnection() { string connectionString = GetConnectionString(); using (SqlConnection connection = new SqlConnection()) { connection.ConnectionString = connectionString; connection.Open(); Console.WriteLine("State: {0}", connection.State); Console.WriteLine("ConnectionString: {0}", connection.ConnectionString); } } static private string GetConnectionString() { // To avoid storing the connection string in your code,   // you can retrieve it from a configuration file.  return "Data Source=MSSQL1;Initial Catalog=AdventureWorks;" + "Integrated Security=true;"; }

 

Below example is using PHP:

 

$link = mysql_connect('localhost', 'mysql_user', 'mysql_password');if (!$link) {    die('Could not connect: ' . mysql_error());}echo 'Connected successfully';mysql_close($link);

Connection String is simply a string that use to connect any type of Database to perform operaation on it. In any Language.

For Example: 

Data Source=myServerAddress;Initial Catalog=myDataBase;Integrated Security=SSPI;

User ID=myDomain\\myUsername;Password=myPassword;

A connection string is a string that specifies information about a data source and the means of connecting to it. It is passed in code to an underlying driver or provider in order to initiate the connection.

 

Example

[SettingsBindableAttribute(true)]

public:

virtual property String^ ConnectionString {

String^ get () override;

void set (String^ value) override;

}

 

 

Exceptions:

ArgumentException -An invalid connection string argument has been supplied, or a required connection string argument has not been supplied.

 

 

For further refer these

 

http://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqlconnection.connectionstring(v=vs.110).aspx?cs-save-lang=1&cs-lang=csharp#code-snippet-1

 

 

 

Other Example in .NET

 

When your application connects to a database or a data file you let ADO or ADO.Net utilize a provider to do the job for you. The connection string contains the information that the provider need to know to be able to establish a connection to the database or the data file.

 

Reqrments

1.A connection string consists of a series of keyword - value pairs separated by semicolons (;)

2.The equal sign (=) connects each keyword and its value

Example: Key1=Value1;Key2=Value2;Key3=Value3;

 

Connection string is the sequence of characters that are used to connect to a database for example jdbc connection string for mysql database would look like 'jdbc:mysql://HOST/DATABASE com.mysql.jdbc.Driver'. HOST will be replaced by address of host machinne and DATABASE will be replaced by database name.

it is a string with special format contains credentials and other necessary information to create a connection with some resource.it is usually used with databases connection especially with oop programming languages.

Connection string  is a user credentials to accress some sort of data (Database, website private pages...etc), it's called connection string because mostly it's passed to the server by one line of code.

 

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