Opening a database connection v126.96.36.199
EDBConnection object is responsible for handling the communication between an instance of EDB Postgres Advanced Server and a .NET application. Before you can access data stored in an EDB Postgres Advanced Server database, you must create and open an
The examples that follow show the basic steps for connecting to an instance of Advanced Server. You must:
- Import the namespace
- Create an instance of
- Initialize the
EDBConnectionobject by passing a connection string as a parameter to the constructor for the
- Call the
Openmethod of the
EDBConnectionobject to open the connection.
A valid connection string specifies location and authentication information for an EDB Postgres Advanced Server instance. You must provide the connection string before opening the connection. A connection string must contain:
- The name or IP address of the server
- The name of the EDB Postgres Advanced Server database
- The name of an EDB Postgres Advanced Server user
- The password associated with that user
You can include the following parameters in the connection string:
CommandTimeout specifies the length of time (in seconds) to wait for a command to finish executing before throwing an exception. The default value is
ConnectionLifeTime to specify the length of time (in seconds) to wait before closing unused connections in the pool. The default value is
Database parameter to specify the name of the database for the application to connect to. The default is the name of the connecting user.
Encoding parameter is obsolete. The parameter always returns the string
unicode and silently ignores attempts to set it.
Specify a value of
true to use Windows Integrated Security. By default,
Integrated Security is set to
false, and Windows Integrated Security is disabled.
Load Role Based Tables
Load Role Based Tables to load table OIDs based on role. This change impacts only the loading of table type OID and not the composite type. Setting this parameter to
true triggers the new functionality. The default value is
EDBConnection to dispose of pooled connections when the pool exceeds the specified number of connections. The default value is
EDBConnection to preallocate the specified number of connections with the server. The default value is
When using clear text authentication, specify the password to use to establish a connection with the server.
Specify a value of
false to disable connection pooling. By default,
Pooling is set to
true to enable connection pooling.
Port parameter specifies the port for the application to connect to.
The specific protocol version to use (instead of automatic). Specify an integer value of
SearchPath parameter to change the search path to named and public schemas.
The name or IP address of the EDB Postgres Advanced Server host.
Specify a value of
true to attempt a secure connection. By default,
SSL is set to
sslmode to specify an SSL connection control preference.
sslmode can be:
prefer — Use SSL if possible.
require — Throw an exception if an SSL connection can't be established.
allow — Connect without SSL. This parameter isn't supported.
disable — Don't attempt an SSL connection. This is the default behavior.
SyncNotification parameter to specify for
EDBDataprovider to use synchronous notifications. The default value is
Timeout specifies the length of time (in seconds) to wait for an open connection. The default value is
User Id parameter specifies the user name to use for the connection.
This example shows how to open a connection to an instance of EDB Postgres Advanced Server and then close the connection. The connection is established using the credentials specified in the
DB_CONN_STRING configuration parameter. See Using the .Net Connector for an introduction to connection information. Also see Connection string parameters for connection parameters.
If the connection is successful, a message appears indicating that the connection opened successfully.
This example opens a connection with an EDB Postgres Advanced Server database using a console-based application.
Before writing the code for the console application, create an
app.config file that stores the connection string to the database. Using a configuration file makes it convenient to update the connection string if the information changes.
Enter the following code sample into a file:
Save the file as
EDBConnection-Sample.cs and compile it with the following command:
csc /r:EnterpriseDB.EDBClient.dll /out:Console.exe EDBConnection-Sample.cs
Compiling the sample generates a
Console.exe file. You can execute the sample code by entering
Console.exe. When executed, the console verifies that it opened successfully.
This example opens a database connection using a .NET WinForm application. To use the example, save the following code as
WinForm-Example.cs in a directory that contains the library files.
Change the database connection string to point to the database that you want to connect to. Then compile the file with the following command:
csc /r:EnterpriseDB.EDBClient.dll /out:WinForm.exe WinForm-Example.cs
This command generates a
WinForm.exe file in the same folder that the executable was compiled under. Invoking the executable displays a message that the connection was successful.