Using Connection String Keywords with SQL Native Client

Data aggiornamento: 17 luglio 2006

Some SQL Native Client APIs use connection strings to specify connection attributes. Connection strings are lists of keyword and associated values; each keyword identifies a particular connection attribute.

[!NOTA] SQL Native Client allows ambiguity in connection strings to maintain backward compatibility (for example, some keywords may be specified more than once, and conflicting keywords may be allowed with resolution based on position or precedence). Future releases of SQL Native Client will not allow ambiguity in connection strings. It is good practice when modifying applications to use SQL Native Client to eliminate any dependency on connection string ambiguity.

The following sections describe the keywords that can be used with the SQL Native Client OLE DB provider, the SQL Native Client ODBC driver, and ActiveX Data Objects (ADO) when using SQL Native Client as the data provider.

OLE DB Provider Connection String Keywords

There are two ways OLE DB applications can initialize data source objects:

• IDBInitialize::Initialize
• IDataInitialize::GetDataSource

In the first case, a provider string can be used to initialize connection properties by setting the property DBPROP_INIT_PROVIDERSTRING in the DBPROPSET_DBINIT property set. In the second case, an initialization string can be passed to IDataInitialize::GetDataSource method to initialize connection properties. Both methods initialize the same OLE DB connection properties, but different sets of keywords are used. The set of keywords used by IDataInitialize::GetDataSource is at minimum the description of properties within the initialization property group.

Boolean properties set in provider strings via DBPROP_INIT_PROVIDERSTRING values are set using the values "yes" and "no." Boolean properties set in initialization strings using IDataInitialize::GetDataSource are set using the values "true" and "false."

Applications using IDataInitialize::GetDataSource can also use the keywords used by IDBInitialize::Initialize but only for properties that do not have a default value. If an application uses both the IDataInitialize::GetDataSource keyword and the IDBInitialize::Initialize keyword in the initialization string, the IDataInitialize::GetDataSource keyword setting is used. It is strongly recommended that applications do not use IDBInitialize::Initialize keywords in IDataInitialize:GetDataSource connection strings, as this behavior may not be maintained in future releases.

Connection strings used by OLE DB applications using DBPROP_INIT_PROVIDERSTRING with IDBInitialize::Initialize have the following syntax:

connection-string ::= empty-string[;] | attribute[;] | attribute; connection-string

empty-string ::=

attribute ::= attribute-keyword=[{]attribute-value[}]

attribute-value ::= character-string

attribute-keyword ::= identifier

Attribute values can optionally be enclosed in braces, and it is good practice to do so. This avoids problems when attribute values contain non-alphanumeric characters. The first closing brace in the value is assumed to terminate the value, so values cannot contain closing brace characters.

The following table describes the keywords that may be used with DBPROP_INIT_PROVIDERSTRING.

Keyword	Initialization property	Description
Addr	SSPROP_INIT_NETWORKADDRESS	Synonym for "Address."
Address	SSPROP_INIT_NETWORKADDRESS	The network address of an instance of SQL Server in the organization.
APP	SSPROP_INIT_APPNAME	The string identifying the application.
AttachDBFileName	SSPROP_INIT_FILENAME	The name of the primary file (include the full path name) of an attachable database. To use AttachDBFileName, you must also specify the database name with the provider string Database keyword. If the database was previously attached, SQL Server does not reattach it (it uses the attached database as the default for the connection).
Auto Translate	SSPROP_INIT_AUTOTRANSLATE	Synonym for "AutoTranslate."
AutoTranslate	SSPROP_INIT_AUTOTRANSLATE	Configures OEM/ANSI character translation. Recognized values are "yes" and "no."
Database	DBPROP_INIT_CATALOG	The database name.
DataTypeCompatibility	SSPROP_INIT_DATATYPECOMPATIBILITY	Specifies the mode of data type handling to use. Recognized values are "0" for provider data types and "80" for SQL Server 2000 data types.
Encrypt	SSPROP_INIT_ENCRYPT	Specifies whether data should be encrypted before sending it over the network. Possible values are "yes" and "no." The default value is "no."
FailoverPartner	SSPROP_INIT_FAILOVERPARTNER	The name of the failover server used for database mirroring.
Language	SSPROPT_INIT_CURRENTLANGUAGE	The SQL Server language.
MarsConn	SSPROP_INIT_MARSCONNECTION	Enables or disables multiple active result sets (MARS) on the connection if the server is SQL Server 2005 or later. Recognized values are "yes" and "no." The default is "no."
Net	SSPROP_INIT_NETWORKLIBRARY	Synonym for "Network."
Network	SSPROP_INIT_NETWORKLIBRARY	The network library used to establish a connection to an instance of SQL Server in the organization.
Network Library	SSPROP_INIT_NETWORKLIBRARY	Synonym for "Network."
PacketSize	SSPROP_INIT_PACKETSIZE	Network packet size. The default is 4096.
PersistSensitive	DBPROP_AUTH_PERSIST_SENSITIVE_AUTHINFO	Accepts the strings "yes" and "no" as values. When "no," the data source object is not allowed to persist sensitive authentication information
PWD	DBPROP_AUTH_PASSWORD	The SQL Server login password.
Server	DBPROP_INIT_DATASOURCE	The name of an instance of SQL Server in the organization.
Timeout	DBPROP_INIT_TIMEOUT	The amount of time (in seconds) to wait for data source initialization to complete.
Trusted_Connection	DBPROP_AUTH_INTEGRATED	When "yes," instructs the SQL Native Client OLE DB provider to use Windows Authentication Mode for login validation. Otherwise instructs the SQL Native Client OLE DB provider to use a SQL Server username and password for login validation, and the UID and PWD keywords must be specified.
TrustServerCertificate	SSPROP_INIT_TRUST_SERVER_CERTIFICATE	Accepts the strings "yes" and "no" as values. The default value is "no," which means that the server certificate will be validated.
UID	DBPROP_AUTH_USERID	The SQL Server login name.
UseProcForPrepare	SSPROP_INIT_USEPROCFORPREP	This keyword is deprecated, and its setting is ignored by the SQL Native Client OLE DB Provider.
WSID	SSPROP_INIT_WSID	The workstation identifier.

Connection strings used by OLE DB applications using IDataInitialize::GetDataSource have the following syntax:

connection-string ::= empty-string[;] | attribute[;] | attribute; connection-string

empty-string ::=

attribute ::= attribute-keyword=[quote]attribute-value[quote]

attribute-value ::= character-string

attribute-keyword ::= identifier

quote ::= " | '

Attribute values can optionally be enclosed in single or double quotes, and it is good practice to do so. This avoids problems when values contain non-alphanumeric characters. The quote character used can also appear in values, provided that it is doubled.

The following table describes the keywords that may be used with IDataInitialize::GetDataSource:

Keyword	Initialization property	Description
Application Name	SSPROP_INIT_APPNAME	The string identifying the application.
Auto Translate	SSPROP_INIT_AUTOTRANSLATE	Synonym for "AutoTranslate."
AutoTranslate	SSPROP_INIT_AUTOTRANSLATE	Configures OEM/ANSI character translation. Recognized values are "true" and "false."
Connect Timeout	DBPROP_INIT_TIMEOUT	The amount of time (in seconds) to wait for data source initialization to complete.
Current Language	SSPROPT_INIT_CURRENTLANGUAGE	The SQL Server language name.
Data Source	DBPROP_INIT_DATASOURCE	The name of an instance of SQL Server in the organization.
DataTypeCompatibility	SSPROP_INIT_DATATYPECOMPATIBILITY	Specifies the mode of data type handling to use. Recognized values are "0" for provider data types and "80" for SQL Server 2000 data types.
Failover Partner	SSPROP_INIT_FAILOVERPARTNER	The name of the failover server used for database mirroring.
Initial Catalog	DBPROP_INIT_CATALOG	The database name.
Initial File Name	SSPROP_INIT_FILENAME	The name of the primary file (include the full path name) of an attachable database. To use AttachDBFileName, you must also specify the database name with the provider string DATABASE keyword. If the database was previously attached, SQL Server does not reattach it (it uses the attached database as the default for the connection).
Integrated Security	DBPROP_AUTH_INTEGRATED	Accepts the value "SSPI" for Windows Authentication.
MARS Connection	SSPROP_INIT_MARSCONNECTION	Enables or disables multiple active result sets (MARS) on the connection if the server is SQL Server 2005 or later. Recognized values are "true" and "false." The default is "false."
Network Address	SSPROP_INIT_NETWORKADDRESS	The network address of an instance of SQL Server in the organization.
Network Library	SSPROP_INIT_NETWORKLIBRARY	The network library used to establish a connection to an instance of SQL Server in the organization.
Packet Size	SSPROP_INIT_PACKETSIZE	Network packet size. The default is 4096.
Password	DBPROP_AUTH_PASSWORD	The SQL Server login password.
Persist Security Info	DBPROP_AUTH_PERSIST_SENSITIVE_AUTHINFO	Accepts the strings "true" and "false" as values. When "false," the data source object is not allowed to persist sensitive authentication information
Provider		For SQL Native Client, this should be "SQLNCLI."
Trust Server Certificate	SSPROP_INIT_TRUST_SERVER_CERTIFICATE	Accepts the strings "true" and "false" as values. The default value is "false," which means that the server certificate will be validated.
Use Encryption for Data	SSPROP_INIT_ENCRYPT	Specifies whether data should be encrypted before sending it over the network. Possible values are "true" and "false." The default value is "false."
User ID	DBPROP_AUTH_USERID	The SQL Server login name.
Workstation ID	SSPROP_INIT_WSID	The workstation identifier.

ODBC Driver Connection String Keywords

ODBC applications use connection strings as a parameters to the SQLDriverConnect and SQLBrowseConnect functions.

Connection strings used by ODBC have the following syntax:

connection-string ::= empty-string[;] | attribute[;] | attribute; connection-string

empty-string ::=

attribute ::= attribute-keyword=[{]attribute-value[}]

attribute-value ::= character-string

attribute-keyword ::= identifier

Attribute values can optionally be enclosed in braces, and it is good practice to do so. This avoids problems when attribute values contain non-alphanumeric characters. The first closing brace in the value is assumed to terminate the value, so values cannot contain closing brace characters.

The following table describes the keywords that may be used with an ODBC connection string.

Keyword	Description
Addr	Synonym for "Address."
Address	The network address of the server running an instance of SQL Server. Address is usually the network name of the server, but can be other names such as a pipe, or a TCP/IP port and socket address. Beginning with SQL Server 2005 Service Pack 1, the value of Address takes precedence over the value passed to Server in ODBC connection strings when using SQL Native Client. Also note that Address=; will connect to the server specified in the Server keyword, whereas Address= ;, Address=.;, and Address=(local); all cause a connection to the local server.
AnsiNPW	When "yes", the driver uses ANSI-defined behaviors for handling NULL comparisons, character data padding, warnings, and NULL concatenation. When "no", ANSI defined behaviors are not exposed. For more information about ANSI NPW behaviors, see Effects of SQL-92 Options.
APP	Name of the application calling SQLDriverConnect (optional). If specified, this value is stored in the master.dbo.sysprocesses column program_name and is returned by sp_who and the APP_NAME functions.
AttachDBFileName	Name of the primary file of an attachable database. Include the full path and escape any \ characters if using a C character string variable: AttachDBFileName=c:\\MyFolder\\MyDB.mdf This database is attached and becomes the default database for the connection. To use AttachDBFileName you must also specify the database name in either the SQLDriverConnect DATABASE parameter or the SQL_COPT_CURRENT_CATALOG connection attribute. If the database was previously attached, SQL Server does not reattach it; it uses the attached database as the default for the connection.
AutoTranslate	When "yes," ANSI character strings sent between the client and server are translated by converting through Unicode to minimize problems in matching extended characters between the code pages on the client and the server. Client SQL_C_CHAR data sent to a SQL Server char, varchar, or text variable, parameter, or column is converted from character to Unicode using the client ANSI code page (ACP), then converted from Unicode to character using the ACP of the server. SQL Server char, varchar, or text data sent to a client SQL_C_CHAR variable is converted from character to Unicode using the server ACP, then converted from Unicode to character using the client ACP. These conversions are performed on the client by the SQL Native Client ODBC driver. This requires that the same ANSI code page (ACP) used on the server be available on the client. These settings have no effect on the conversions that occur for these transfers: Unicode SQL_C_WCHAR client data sent to char, varchar, or text on the server. char, varchar, or text server data sent to a Unicode SQL_C_WCHAR variable on the client. ANSI SQL_C_CHAR client data sent to Unicode nchar, nvarchar, or ntext on the server. Unicode nchar, nvarchar, or ntext server data sent to an ANSI SQL_C_CHAR variable on the client. When "no," character translation is not performed. The SQL Native Client ODBC driver does not translate client ANSI character SQL_C_CHAR data sent to char, varchar, or text variables, parameters, or columns on the server. No translation is performed on char, varchar, or text data sent from the server to SQL_C_CHAR variables on the client. If the client and SQL Server are using different ACPs, extended characters may be misinterpreted.
Database	Name of the default SQL Server database for the connection. If Database is not specified, the default database defined for the login is used. The default database from the ODBC data source overrides the default database defined for the login. The database must be an existing database unless AttachDBFileName is also specified. If AttachDBFileName is also specified, the primary file it points to is attached and given the database name specified by Database.
Driver	Name of the driver as returned by SQLDrivers. The keyword value for the SQL Native Client ODBC driver is "{SQL Native Client}". The Server keyword is required if Driver is specified and DriverCompletion is set to SQL_DRIVER_NOPROMPT.
DSN	Name of an existing ODBC user or system data source.
Encrypt	Specifies whether data should be encrypted before sending it over the network. Possible values are "yes" and "no". The default value is "no".
Fallback	This keyword is deprecated, and its setting is ignored by the SQL Native Client ODBC driver.
Failover_Partner	Name of the failover partner server to be used if a connection cannot be made to the primary server.
FileDSN	Name of an existing ODBC file data source.
Language	SQL Server language name (optional). SQL Server can store messages for multiple languages in sysmessages. If connecting to a SQL Server with multiple languages, Language specifies which set of messages are used for the connection.
MARS_Connection	Enables or disables multiple active result sets (MARS) on the connection if the server is SQL Server 2005 or later. Recognized values are "yes" and "no." The default is "no."
Net	Synonym for "Network."
Network	When dbnmpntw named pipes are used, when dbmssocn TCP/IP are used. Using this keyword is not recommended; use SQL Server Configuration Manager to specify network protocols instead.
PWD	The password for the SQL Server login account specified in the UID parameter. PWD need not be specified if the login has a NULL password or when using Windows Authentication (Trusted_Connection = yes).
QueryLog_On	When "yes," logging long-running query data is enabled on the connection. When "no," long-running query data is not logged.
QueryLogFile	Full path and file name of a file to use to log data on long-running queries.
QueryLogTime	Digit character string specifying the threshold (in milliseconds) for logging long-running queries. Any query that does not get a response in the time specified is written to the long-running query log file.
QuotedId	When "yes," QUOTED_IDENTIFIERS is set ON for the connection, SQL Server uses the SQL-92 rules regarding the use of quotation marks in SQL statements. When no, QUOTED_IDENTIFIERS is set OFF for the connection. SQL Server then follows the legacy Transact-SQL rules regarding the use of quotation marks in SQL statements. For more information, see Effects of SQL-92 Options.
Regional	When "yes," the SQL Native Client ODBC driver uses client settings when converting currency, date, and time data to character data. The conversion is one way only; the driver does not recognize non-ODBC standard formats for date strings or currency values within; for example, a parameter used in an INSERT or UPDATE statement. When "no," the driver uses ODBC standard strings to represent currency, date, and time data that is converted to character data.
SaveFile	Name of an ODBC data source file into which the attributes of the current connection are saved if the connection is successful.
Server	The name of an instance of SQL Server to connect to. The value must be either the name of a server on the network, or the name of a SQL Server Configuration Manager advanced server entry. You can enter (local) as the server name to connect to a copy of SQL Server running on the same computer. SQL Server 2000 and later supports multiple instances of SQL Server running on the same computer. To specify a named instance of SQL Server, the server name is specified as ServerName\InstanceName. Server is required. Beginning with SQL Server 2005 Service Pack 1, spaces are ignored at the beginning of the value passed to Server in ODBC connection strings when using SQL Native Client.
StatsLog_On	When "yes," enables the capture of SQL Native Client ODBC driver performance data. When "no," SQL Native Client ODBC driver performance data is not available on the connection.
StatsLogFile	Full path and file name of a file used to record SQL Native Client ODBC driver performance statistics.
Trusted_Connection	When "yes," instructs the SQL Native Client ODBC driver to use Windows Authentication Mode for login validation. Otherwise instructs the SQL Native Client ODBC driver to use a SQL Server username and password for login validation, and the UID and PWD keywords must be specified.
TrustServerCertificate	When used with Encrypt, enables encryption using a self-signed server certificate.
UID	A valid SQL Server login account. UID need not be specified when using Windows Authentication.
UseProcForPrepare	This keyword is deprecated, and its setting is ignored by the SQL Native Client ODBC Driver.
WSID	The workstation ID. Typically, this is the network name of the computer on which the application resides (optional). If specified, this value is stored in the master.dbo.sysprocesses column hostname and is returned by sp_who and the HOST_NAME function.

[!NOTA] Regional conversion settings apply to currency, numeric, date, and time data types. The conversion setting is only applicable to output conversion and is only visible when currency, numeric, date, or time values are converted to character strings.

The SQL Native Client ODBC driver uses the locale registry settings for the current user. The driver does not honor the current thread's locale if the application sets it after connection by, for example, calling SetThreadLocale.

Altering the regional behavior of a data source can cause application failure. An application that parses date strings, and expects date strings to appear as defined by ODBC, could be adversely affected by altering this value.

ActiveX Data Objects (ADO) Connection String Keywords

ADO applications set the ConnectionString property of ADODBConnection objects or supply a connection string as a parameter to the Open method of ADODBConnection objects.

ADO applications can also use the keywords used by the OLE DB IDBInitialize::Initialize method, but only for properties that do not have a default value. If an application uses both the ADO keywords and the IDBInitialize::Initialize keywords in the initialization string, the ADO keyword setting will be used. It is strongly recommended that applications only use ADO connection string keywords.

Connection strings used by ADO have the following syntax:

connection-string ::= empty-string[;] | attribute[;] | attribute; connection-string

empty-string ::=

attribute ::= attribute-keyword=["]attribute-value["]

attribute-value ::= character-string

attribute-keyword ::= identifier

Attribute values can optionally be enclosed in double quotes, and it is good practice to do so. This avoids problems when values contain non-alphanumeric characters. Attribute values cannot contain double quotes.

The following table describes the keywords that may be used with an ADO connection string:

Keyword	Initialization property	Description
Application Name	SSPROP_INIT_APPNAME	The string identifying the application.
Auto Translate	SSPROP_INIT_AUTOTRANSLATE	Synonym for "AutoTranslate."
AutoTranslate	SSPROP_INIT_AUTOTRANSLATE	Configures OEM/ANSI character translation. Recognized values are "true" and "false."
Connect Timeout	DBPROP_INIT_TIMEOUT	The amount of time (in seconds) to wait for data source initialization to complete.
Current Language	SSPROPT_INIT_CURRENTLANGUAGE	The SQL Server language name.
Data Source	DBPROP_INIT_DATASOURCE	The name of an instance of SQL Server in the organization.
DataTypeCompatibility	SSPROP_INIT_DATATYPECOMPATIBILITY	Specifies the mode of data type handling that will be used. Recognized values are "0" for provider data types and "80" for SQL Server 2000 data types.
Failover Partner	SSPROP_INIT_FAILOVERPARTNER	The name of the failover server used for database mirroring.
Initial Catalog	DBPROP_INIT_CATALOG	The database name.
Initial File Name	SSPROP_INIT_FILENAME	The name of the primary file (include the full path name) of an attachable database. To use AttachDBFileName, you must also specify the database name with the provider string DATABASE keyword. If the database was previously attached, SQL Server does not reattach it (it uses the attached database as the default for the connection).
Integrated Security	DBPROP_AUTH_INTEGRATED	Accepts the value "SSPI" for Windows Authentication.
MARS Connection	SSPROP_INIT_MARSCONNECTION	Enables or disables multiple active result sets (MARS) on the connection if the server is SQL Server 2005 or later. Recognized values are "true" and "false".The default is "false."
Network Address	SSPROP_INIT_NETWORKADDRESS	The network address of an instance of SQL Server in the organization.
Network Library	SSPROP_INIT_NETWORKLIBRARY	The network library used to establish a connection to an instance of SQL Server in the organization.
Packet Size	SSPROP_INIT_PACKETSIZE	Network packet size. The default is 4096.
Password	DBPROP_AUTH_PASSWORD	The SQL Server login password.
Persist Security Info	DBPROP_AUTH_PERSIST_SENSITIVE_AUTHINFO	Accepts the strings "true" and "false" as values. When "false" the data source object is not allowed to persist sensitive authentication information
Provider		For SQL Native Client, this should be "SQLNCLI."
Trust Server Certificate	SSPROP_INIT_TRUST_SERVER_CERTIFICATE	Accepts the strings "true" and "false" as values. The default value is "false," which means that the server certificate will be validated.
Use Encryption for Data	SSPROP_INIT_ENCRYPT	Specifies whether data should be encrypted before sending it over the network. Possible values are "true" and "false". The default value is "false."
User ID	DBPROP_AUTH_USERID	The SQL Server login name.
Workstation ID	SSPROP_INIT_WSID	The workstation identifier.

Change History

Release	History
17 luglio 2006	New content: Updated ODBC Address and Server keyword descriptions.

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