Connection string

In computing, 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. Whilst commonly used for a database connection, the data source could also be a spreadsheet or text file.

The connection string may include attributes such as the name of the driver, server and database, as well as security information such as user name and password.

Examples

This example shows a PostgreSQL connection string for connecting to wikipedia.com with SSL and a connection timeout of 180 seconds:

DRIVER={PostgreSQL Unicode};SERVER=www.wikipedia.com;SSL=true;SSLMode=require;DATABASE=wiki;UID=wikiuser;Connect Timeout=180;PWD=ashiknoor

Users of Oracle databases can specify connection strings:

on the command line (as in: sqlplus scott/tiger@connection_string )
via environment variables ($TWO_TASK in Unix-like environments; %TWO_TASK% in Microsoft Windows environments)^[1]
in local configuration files (such as the default $ORACLE_HOME/network/admin.tnsnames.ora)^[2]
in LDAP-capable directory services

References

^ Watt, Simon; et al. (June 2005). "Configuring SQL*Plus". SQL*Plus User's Guide and Reference: Release 10.2. Redwood City: Oracle Corporation. Retrieved 26 August 2010. LOCAL [:] Windows environment variable to specify a connection string. Performs the same function as TWO_TASK on UNIX.
^ Kyte, Thomas (2005). Expert Oracle database architecture: 9i and 10g programming techniques and solutions. Apress series. Apress. p. 60. ISBN 978-1-59059-530-5. Retrieved 26 August 2010. The TNS connection string tells the Oracle software how to connect to the remote database. Generally, the client software [...] will read a file called tnsnames.ora. This is a plaint-text configuration file commonly found in the [ORACLE_HOME]\network\admin directory ([ORACLE_HOME] represents the full path to your Oracle installation directory).