Oracle connection strings

.NET Framework Data Provider for Oracle

Standard

Data Source=MyOracleDB;Integrated Security=yes;

This one works only with Oracle 8i release 3 or later

Omiting tnsnames.ora

This is another type of Oracle connection string that doesn't rely on you to have a DSN for the connection. You create a connection string based on the format used in the tnsnames.ora file without the need to actually have one of these files on the client pc.

SERVER=(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=MyHost)(PORT=MyPort))(CONNECT_DATA=(SERVICE_NAME=MyOracleSID)));uid=myUsername;pwd=myPassword;

Omiting tnsnames.ora Alternative

Some reported problems with the one above and Visual Studio. Use the next one if you've encountered problems.

Data Source=(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=MyHost)(PORT=MyPort))(CONNECT_DATA=(SERVICE_NAME=MyOracleSID)));User Id=myUsername;Password=myPassword;

Using Connection Pooling

The connection pooling service will create a new pool if it can't find any existing pool that exactly match the new connections connection string properties. If there is a matching pool a connection will be recycled from that pool.

Data Source=myOracleDB;User Id=myUsername;Password=myPassword;Min Pool Size=10;Connection Lifetime=120;Connection Timeout=60;Incr Pool Size=5;Decr Pool Size=2;

The first connection opened creates the connection pool. The service initially creates the number of connections defined by the Min Pool Size parameter.

The Incr Pool Size attribute defines the number of new connections to be created by the connection pooling service when more connections are needed.

When a connection is closed, the connection pooling service determines whether the connection lifetime has exceeded the value of the Connection Lifetime attribute. If so, the connection is closed; otherwise, the connection goes back to the connection pool.

The connection pooling service closes unused connections every 3 minutes. The Decr Pool Size attribute specifies the maximum number of connections that can be closed every 3 minutes.

Utilizing the Password Expiration functionality

First open a connection with a connection string. When the connection is opened, an error is raised because the password have expired. Catch the error and execute the OpenWithNewPassword command supplying the new password.

Data Source=myOracleDB;User Id=myUsername;Password=myPassword;

oConn.OpenWithNewPassword(sTheNewPassword);

Proxy Authentication

Data Source=myOracleDB;User Id=myUsername;Password=myPassword;Proxy User Id=pUserId;Proxy Password=pPassword;

Oracle Data Provider for .NET / ODP.NET

Using TNS

Data Source=TORCL;User Id=myUsername;Password=myPassword;

Using the Easy Connect Naming Method (aka EZ Connect)

The easy connect naming method enables clients to connect to a database without any configuration.

Data Source=username/password@//myserver:1521/my.service.com;

Port 1521 is used if no port number is specified in the connection string.

Make sure that EZCONNECT is enabled in the sqlnet.ora file. NAMES.DIRECTORY_PATH= (TNSNAMES, EZCONNECT)

'//' in data source is optional and is there to enable URL style hostname values

Specifying Pooling parameters

By default, connection pooling is enabled. This one controls the pooling mechanisms. The connection pooling service creates connection pools by using the ConnectionString property to uniquely identify a pool.

Data Source=myOracle;User Id=myUsername;Password=myPassword;Min Pool Size=10;Connection Lifetime=120;Connection Timeout=60;Incr Pool Size=5;Decr Pool Size=2;

The first connection opened creates the connection pool. The service initially creates the number of connections defined by the Min Pool Size parameter.

The Incr Pool Size attribute defines the number of new connections to be created by the connection pooling service when more connections are needed.

When a connection is closed, the connection pooling service determines whether the connection lifetime has exceeded the value of the Connection Lifetime attribute. If so, the connection is closed; otherwise, the connection goes back to the connection pool.

The connection pooling service closes unused connections every 3 minutes. The Decr Pool Size attribute specifies the maximum number of connections that can be closed every 3 minutes.

Restricting Pool size

Use this one if you want to restrict the size of the pool.

Data Source=myOracle;User Id=myUsername;Password=myPassword;Max Pool Size=40;Connection Timeout=60;

The Max Pool Size attribute sets the maximum number of connections for the connection pool. If a new connection is requested, but no connections are available and the limit for Max Pool Size has been reached the connection pooling service waits for the time defined by the Connection Timeout attribute. If the Connection Timeout time has been reached, and there are still no connections available in the pool, the connection pooling service raises an exception indicating that the request has timed-out.

Using Windows user authentication

Oracle can open a connection using Windows user login credentials to authenticate database users.

Data Source=myOracle;User Id=/;

If the Password attribute is provided, it is ignored.

Operating System Authentication is not supported in a .NET stored procedure.

Privileged Connections

Oracle allows database administrators to connect to Oracle Database with either SYSDBA or SYSOPER privileges.

Data Source=myOracle;User Id=myUsername;Password=myPassword;DBA Privilege=SYSDBA;

SYSOPER is also valid for the DBA Privilege attribute.

Runtime Connection Load Balancing

Optimizes connection pooling for RAC database by balancing work requests across RAC instances.

Data Source=myOracle;User Id=myUsername;Password=myPassword;Load Balancing=True;

This feature can only be used against a RAC database and only if pooling is enabled (default).

Oracle in XEClient

Standard

Oracle XE (or "Oracle Database 10g Express Edition") is a simple version that's free to distribute.

Driver=(Oracle in XEClient);dbq=111.21.31.99:1521/XE;Uid=myUsername;Pwd=myPassword;

Oracle in OraClient11g_home1

Standard

Driver={Oracle in OraClient11g_home1};Dbq=myTNSServiceName;Uid=myUsername;Pwd=myPassword;

Server SID

Driver={Oracle in OraClient11g_home1};Server=serverSID;Uid=myUsername; Pwd=myPassword;

Both Server and Dbq

ODBC;Driver={Oracle in OraClient11g_home1};SERVER=[server SID];UID=[userid];PWD=[password];DBQ=[server SID];

Some feedback on using both Dbq and Server keywords to make this work.

Oracle Provider for OLE DB

Trusted Connection

This one specifies OS authentication to be used when connecting to an Oracle database.

Provider=OraOLEDB.Oracle;Data Source=MyOracleDB;OSAuthent=1;

Oracle XE, VB6 ADO

Provider=OraOLEDB.Oracle;dbq=localhost:1521/XE;Database=myDataBase;User Id=myUsername;Password=myPassword;

Oracle XE, C++ ADO

Provider=OraOLEDB.Oracle;Data Source=localhost:1521/XE;Initial Catalog=myDataBase;User Id=myUsername;Password=myPassword;

TNS-less connection string

Provider=OraOLEDB.Oracle;Data Source=(DESCRIPTION=(CID=GTU_APP)(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=myHost)(PORT=myPort)))(CONNECT_DATA=(SID=MyOracleSID)(SERVER=DEDICATED)));User Id=myUsername;
Password=myPassword;

Controling rowset cache mechanism

Specifies the type of caching used by the provider to store rowset data. OraOLEDB provides two caching mechanisms; File and Memory.

Provider=OraOLEDB.Oracle;Data Source=MyOracleDB;User Id=myUsername;Password=myPassword;CacheType=File;

Memory is the default value. All the rowset data is stored in-memory which provides better performance at the expense of higher memory utilization.

File = All the rowset data is stored on disk. This caching mechanism limits the memory consumption at the expense of performance.

Controling the fetchsize

This one specifies the number of rows the provider will fetch at a time (fetch array).

Provider=OraOLEDB.Oracle;Data Source=MyOracleDB;User Id=myUsername;Password=myPassword;FetchSize=200;

The FetchSize value must be set appropriately depending on the data size and the response time of the network. If the value is set too high, this could result in more wait time during the execution of the query. If the value is set too low, this could result in many more round trips to the database. Valid values are 1 to 429,496,296. The default is 100.

Controling the chunksize

This one specifies the size, in bytes, of the data in LONG and LONG RAW columns fetched and stored in the provider cache.

Provider=OraOLEDB.Oracle;Data Source=MyOracleDB;User Id=myUsername;Password=myPassword;ChunkSize=200;

Providing a high value for this attribute improves performance, but requires more memory to store the data in the rowset. Valid values are 1 to 65535. The default is 100.

Using with Microsofts OLE DB .NET Data Provider

The Microsoft OLE DB .NET Data Provider can utilize OraOLEDB as the OLE DB Provider for accessing Oracle. However this must be enabled in the connection string.

Provider=OraOLEDB.Oracle;Data Source=MyOracleDB;User Id=myUsername;Password=myPassword;OLEDB.NET=True;

The OLEDB.NET connection string attribute must not be used in ADO applications.

Using OraOLEDB Custom Properties with Microsofts OLE DB .NET Data Provider

The SPPrmsLOB and NDatatype properties can only be set as connection string attributes when OraOLEDB is used by OLE DB .NET Data Provider.

Provider=OraOLEDB.Oracle;Data Source=MyOracleDB;User Id=myUsername;Password=myPassword;OLEDB.NET=True;SPPrmsLOB=False;NDatatype=False;SPPrmsLOB=False;

Using ADO, these properties would have been set as a property on the command. This is not possible if using the Microsofts OLE DB .NET Data Provider. So the properties are specified in the connection string instead.

PLSQLRSet: If the stored procedure, provided by the consumer, returns a rowset, PLSQLRSet must be set to TRUE (enabled).

NDatatype: This property allows the consumers to specify whether any of the parameters bound to the command are of Oracle's N datatypes (NCHAR, NVARCHAR or NCLOB). This information is required by OraOLEDB to detect and bind the parameters appropriately. This property should not be set for commands executing SELECT statements. However, this property must be set for all other SQLs such as INSERT, UPDATE, and DELETE.

SPPrmsLOB: This property allows the consumer to specify whether one or more of the parameters bound to the stored procedures are of Oracle's LOB datatype (CLOB, BLOB, or NCLOB). OraOLEDB requires this property to be set to TRUE, in order to fetch the parameter list of the stored procedure prior to execution. The use of this property limits the processing overhead to stored procedures having one or more LOB datatype parameters.

Using distributed transactions

This one specifies sessions to enlist in distributed transactions. This is the default behaviour.

Provider=OraOLEDB.Oracle;Data Source=MyOracleDB;User Id=myUsername;Password=myPassword;DistribTX=1;

Valid values are 0 (disabled) and 1 (enabled).

.NET Framework Data Provider for OLE DB

Use an OLE DB provider from .NET

Provider=any oledb provider's name;OledbKey1=someValue;OledbKey2=someValue;

See the respective OLEDB provider's connection strings options. The .net OleDbConnection will just pass on the connection string to the specified OLEDB provider. Read more here.

Use 'Oracle Provider for OLE DB' from .NET

Provider=OraOLEDB.Oracle;Data Source=MyOracleDB;User Id=myUsername;Password=myPassword;OLEDB.NET=True;

Note! The keyword "OLEDB.NET" must be set to "True" for the OraOLEDB.Oracle provider to function with the .NET Framework Data Provider for OLE DB.

Microsoft ODBC for Oracle

New version

Driver={Microsoft ODBC for Oracle};Server=myServerAddress;Uid=myUsername;Pwd=myPassword;

Connect directly

No TSN nor DSN required.

Driver={Microsoft ODBC for Oracle};Server=(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=199.199.199.199)(PORT=1523))(CONNECT_DATA=(SID=dbName)));Uid=myUsername;Pwd=myPassword;

Without TSN.ora alternative

Driver={Microsoft ODBC for Oracle};CONNECTSTRING=(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=server)(PORT=7001))(CONNECT_DATA=(SERVICE_NAME=myDb)));Uid=myUsername;Pwd=myPassword;