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| Devart.Data.Oracle Namespace > OracleConnection Class : ConnectionString Property (OracleConnection) |
| | Devart.Data.Oracle | Send comments on this topic. |
| Devart.Data.Oracle Namespace > OracleConnection Class : ConnectionString Property (OracleConnection) |
Gets or sets the string used to open an Oracle server database.
[Visual Basic]
Public Property ConnectionString As String [C#]
public string ConnectionString {get; set;}The connection string that includes the source database name, and other parameters needed to establish the initial connection. The default value is an empty string ("").
The ConnectionString property can be set only when the connection is closed; setting ConnectionString of an opened connection closes this connection. Many of the connection string values have corresponding properties. When the connection string is set, all of these properties are updated, except when an error is detected. In this case, none of the properties are updated. OracleConnection properties return only those settings contained in the ConnectionString.
Resetting the ConnectionString on a closed connection resets all connection string values (and related properties) including the password. For example, if you set a connection string that includes "Home = OraClient11g_Home1", and then reset the connection string to "Data Source=ora; User ID = Scott; Password = tiger", the Home property is no longer set to 'OraClient11g_Home1'.
The connection string is parsed immediately after being set. If errors in syntax are found when parsing, a runtime exception, such as
The ConnectionString property format is the same as for common ADO.NET connection strings. Connection string consists of pairs of parameter name and parameter value connected by the equal sign (=). Each pair should be separated from the previous one by a semicolon. Parameter values may be specified inside single or double qotes, (for example, name='value' or name="value"). Either single or double quotes may be used in a value if it is set using another type of quotes, for example, name="value's" or name= 'value"s', but not name= 'value's' or name= ""value"". If a semicolon is a part of a value, the value must be quoted. All blank characters, except those placed within a value or within quotes, are ignored. No escape sequences are supported. The value type is irrelevant. Parameter names are case insensitive. Arguments names may occur only once in the connection string.
The following table lists the valid names for values within the ConnectionString.
| Name | Description |
|---|---|
| Connect Mode | Allows to open a session with administrative privileges SYSDBA or SYSOPER. |
| Connection Class | Connection class for Oracle's Database Resident Connection Pooling (DRCP). You need to set also OCI Session Pooling = true for using DRCP. DRCP is supported starting with Oracle 11g. |
| Connection Lifetime | When a connection is returned to the pool, its creation time is compared with the current time, and the connection is destroyed if that time span (in seconds) exceeds the value specified by Connection Lifetime. The default value is 0. |
| Connection Timeout | Time (in seconds) to wait while trying to establish a connection before terminating the attempt and generating an error. A value of 0 indicates no limit. The default value is 15 seconds. |
| Data Source -or- Server -or- Host | The name of TNS alias of Oracle database to which to connect. For more information refer to Server property. |
| Default Command Timeout | The time in seconds to wait while trying to execute a command before terminating the attempt and generating an error. 0 indicates no limit. |
| Direct | If true, dotConnect for Oracle can operate without an Oracle client installed. The default value is false. |
| Enlist | Determines whether the connection is automatically enlisted in the current distributed transaction. The default value is true. This parameter is not available in Mobile Edition. |
| Home | The Oracle Home that will be used. |
| Initialization Command | Specifies the size of a block (in megabytes) to read/write CLOB or NCLOB data from/to database. This option is supported in OCI mode only. Applicable only for Unicode Oracle servers. Default value is 0, which means that the whole value is sent in one block. If you get errors when reading/writing huge LOB values, try setting this property to 8, it is the safest value. |
| Lob Block Size | Specifies a database-specific command that should be executed immediately after establishing the connection. |
| Max Pool Size | The maximum number of connections allowed in the pool. Setting the Max Pool Size value of the ConnectionString can affect performance. The default value is 100. |
| Min Pool Size | The minimum number of connections allowed in the pool. The default value is 0. |
| Number Mappings | Sets the number mappings used for this connection. Each mapping is set as (OracleNumberType, FromPrecision, ToPrecision, SystemType), where: - OracleNumberType is one of the values from OracleNumberType enumeration; Several mappings should be separated by commas and covered by a common parentheses. For example, this property may be set as: |
| Oci Session Pooling | If true, enables the OCI Session Pooling feature. In this mode the dotConnect for Oracle pool is disabled. |
| Oci Session Pool Allow Waiting | If true, new connections wait for an existing one to close if Max Size is reached; otherwise an exception is thrown. |
| Oci Session Pool Connection Lifetime | This attribute specifies the lifetime of the connection in seconds. Before the Connection is placed back into the pool, the lifetime of the connection is checked. If the lifetime of the connection exceeds this property value, the connection is closed and disposed. If this property value is 0, the connection lifetime is never checked. |
| Oci Session Pool Increment | Allows applications to set the next increment for sessions to be started if the current number of sessions is less than Max Size. The valid values are 1 and above. |
| Oci Session Pool Max Size | Specifies the maximum number of sessions that can be opened in the session pool. Once this value is reached, no more sessions are opened. The valid values are 1 and above. |
| Oci Session Pool Min Size | Specifies the minimum number of sessions in the session pool. This number of sessions are started initially. After this, sessions are opened only when necessary. |
| Oci Session Pool Password | If set, defines password for proxy user. |
| Oci Session Pool User Id | If set, defines user name for proxy user. Available only when OCI Session Pooling is enabled. If you want to have proxy connections without OCI Session Pooling, use the Open overload that accepts another OracleConnection as argument. |
| OraMts | If set to true, Oracle Services for Microsoft Transaction Server (OraMTS) is used for distributed transactions; otherwise OraMTS is not used. |
| Pass Parameters By Name | Pass parameters by name to the stored procedure calls. If set to true, parameters will be passed by name regardless of individual OracleCommand.PassParametersByName values. Default value is false. |
| Password | The password for the Oracle login account. Leave blank if you want to use Integrated Security connections (OS authentication) |
| Pooling | If true, by default, the OracleConnection object is drawn from the appropriate pool or is created and added to the appropriate pool. |
| Port | Number of a port to communicate with listener on the server to use in OracleConnection.Direct mode. The default value is 1521. |
| Service Name | Alias to an Oracle database instance (or many instances) to use in the OracleConnection.Direct mode. The default value is empty string. When Service Name is specified and implies several database instances, dotConnect for Oracle connects to the first instance provided by Oracle listener. Note that RAC is not supported in the Direct mode, and provider works only with this one database instance. |
| SID | Unique name for an Oracle database instance to use in the OracleConnection.Direct mode. The default value is empty string. |
| Statement Cache Size | This attribute enables or disables statement caching. Its value specifies the maximum number of statements that can be cached for a connection. By default this attribute is set to 0 (disabled). Statement caching starts if this parameter is set to a value more than 0. It should not be more than MAX_OPEN_CURSORS parameter in an Oracle database. |
| Transaction Scope Local | If there are several connections with the same connection string (which includes "Transaction Scope Local=true;") within a scope of TransactionScope, our provider will use only one connection internally. The default value is false. Not available in Mobile Edition. |
| Trim Fixed Char | Specifies whether to trim trailing spaces when reading data from fixed-length string data types (CHAR, NCHAR). It affects all command objects of this connection. Behaviour of data reader depends on Trim Fixed Char value at the moment of opening data reader. The default value is true. |
| Unicode | Specifies whether dotConnect for Oracle uses UTF16 mode API calls. The default value is false. |
| User ID -or- User | The Oracle login account. Leave blank if you want to use Integrated Security connections (OS authentication). |
| Validate Connection | Specifies whether to validate connections that are being got from the pool. |
The following example creates an OracleConnection and sets some of its properties in the connection string.
[C#]
public void CreateOraConnection()
{
string oracleConnectionString1 = "User ID=Scott; Password=tiger; Data Source=ORA";
OracleConnection oracleConnection1 = new OracleConnection(oracleConnectionString1);
oracleConnection1.Open();
string oracleConnectionString2 =
"User ID=Scott; Password=tiger; Direct = true; Host=ORA; Service Name=SID; Port=1521;";
OracleConnection oracleConnection2 = new OracleConnection(oracleConnectionString2);
oracleConnection2.Open();
} [Visual Basic]
Public Sub CreateOraConnection()
Dim OracleConnectionString1 As String = "User ID=Scott; Password=tiger; Data Source=ORA"
Dim OracleConnection1 As New OracleConnection(OracleConnectionString1)
OracleConnection1.Open()
Dim OracleConnectionString2 As String = _
"User ID=Scott; Password=tiger; Direct = true; Host=ORA; Service Name=SID; Port=1521;"
Dim OracleConnection2 As New OracleConnection(OracleConnectionString2)
OracleConnection2.Open()
End SubOracleConnection Class | OracleConnection Members | Open Method
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