Sybase

Connecting to a database

Transaction isolation levels

Working with Long or Lob(CLob, BLob) data

Returning output parameters

Cancelling queries

Connection, command, parameter and field options

Getting native Sybase API

Getting native Sybase connection related handles

Getting native Sybase command related handles

Error handling

Special header files - Compile time

Connecting to a database

To connect to a database you should create a connection object and then connect it. A connection object is represented by SAConnection class. After the connection is created you need to connect it to Sybase server using SAConnection::Connect method

void Connect( const SAString &sDBString, const SAString &sUserID, const SAString &sPassword, SAClient_t eSAClient = SA_Client_NotSpecified );

with the following parameters:

sDBString.    One of the following formats:

• "" or "@" - empty string or '@' character, connects to a default database on a default server.
• <database name> or @ <database name>- connects to a database with the specified name on your default server.
• <server name>@- connects to a default database on the specified server.
• <server name>@<database name> - connects to a database with the specified name on the specified server.

sUserID.    A string containing a user name to use when establishing the connection.
sPassword.    A string containing a password to use when establishing the connection.
eSAClient.    Optional. One of the following values from SAClient_t enum:

• SA_Sybase_Client    Sybase client.
• SA_Client_NotSpecified     Used by default if eSAClientparameter is omitted.  You can use this default value only if you have call SAConnection::setClient method with SA_Sybase_Client constant before.

The SQLAPI++ Library requires Open Client version 10.0 or higher.

For more details see How To - Connecting to databases, SAConnection object, SAConnection::Connect.

Transaction isolation levels

SQL-92 defines four isolation levels, all of which are supported by SQLAPI++:

• Read uncommitted (the lowest level where transactions are isolated just enough to ensure that physically corrupt data is not read)
• Read committed
• Repeatable read
• Serializable (the highest level, where transactions are completely isolated from one another)

SQLAPI++ maps different isolation levels on Sybase server in the following way:

      SA_ReadUncommitted = CS_OPT_LEVEL0 ('read uncommitted')
      SA_ReadCommitted = CS_OPT_LEVEL1 ('read committed')
      SA_RepeatableRead = CS_OPT_LEVEL2 ('repeatable read')
      SA_Serializable = CS_OPT_LEVEL3 ('serializable')

For more details see SAConnection::setIsolationLevel.

Working with Long or Lob(CLob, BLob) data

SQLAPI++ supports four types for working with Long or Lob(CLob, BLob) data:

Name	C enum constant
LongBinary	SA_dtLongBinary
LongChar	SA_dtLongChar
BLob (Binary Large object)	SA_dtBLob
CLob (Character Large object)	SA_dtCLob

The table below shows how SQLAPI++ data types correspond with servers original data types:

SA_dtLongBinary <= > IMAGE
SA_dtLongChar <= > TEXT
SA_dtBLob = > IMAGE
SA_dtCLob => TEXT

For more details see How To - Working with Long or Lob(CLob, BLob) data

Returning output parameters

Sybase ASE server does not provide information about parameter's direction type, that's why SQLAPI++ Library defines all parameters (except status result code) as input (SA_ParamInput). If you have input-output parameters in the procedure you have to call SAParam::setParamDirType method for these parameters before command execution and set parameter's direction type explicitly.
You shouldn't call this method for procedure status result code because it is detected correctly (as SA_ParamReturn) by the Library.

There is no need to call this method for Sybase ASA because all parameters are detected correctly automatically (including the direction type).

For more details see SAParam::setParamDirType.

In Sybaseserver stored procedures can have integer return codes and output parameters. The return codes and output parameters are sent in the last packet from the server and are therefore not available to the application until all result sets from stored procedure (if any) are completely processed using SACommand::FetchNext method.

SQLAPI++ Library automatically creates SAParamobject to represent procedure status return code. You can refer to this SAParam object using SQLAPI++ predefined name "RETURN_VALUE".

For more details see SACommand::Execute, SAParam object, How To - Returning Output Parameters.

Cancelling queries

Sybase does not support queries cancelling.

Connection, command, parameter and field options

A server specific option can relate to a connection, command,  parameter or field. We recommend you specify each option in an appropriate object, although it is possible to specify them in the parental object as well. In that case the option affects all the child objects.

A connection related option must be specified in a  SAConnection object.

A command related option may be specified in either SAConnection object or SACommand object. If it is specified in SAConnection object it affects all the commands on that connection.

A parameter related option may be specified in SAConnection object, SACommand object or SAParam object. If it is specified in SAConnection object it affects all the commands and therefore all the parameters on that connection. If it is specified in SACommand object it affects all the parameters on that command.

A field related option may be specified in SAConnection object, SACommand object or SAField object. If it is specified in SAConnection object it affects all the commands and therefore all the fields on that connection. If it is specified in SACommand object it affects all the fields on that command.

Specific options for Sybase:

Option name / Scope	Description
CS_PACKETSIZE Connection related. Should be specified before actual connection is made.	Determines the packet size that Client-Library uses when sending Tabular Data Stream (TDS) packets. For more information see Sybase documentation. Valid values: String containing packet size, see Sybase documentation. Default value: see Sybase documentation.
CS_APPNAME or APPNAME Connection related. Should be specified before actual connection is made.	Defines the application name that a connection will use when connecting to a server. For more information see Sybase documentation. Valid values: see Sybase documentation. Default value: see Sybase documentation.
CS_HOSTNAME or WSID Connection related. Should be specified before actual connection is made.	Declares the name of the host machine, used when logging in to a server. For more information see Sybase documentation. Valid values: see Sybase documentation. Default value: see Sybase documentation.
CS_BULK_LOGIN Connection related. Should be specified before actual connection is made.	Describes whether or not a connection can perform bulk copy operations into a database. For information on Bulk Copy, see the Sybase Common Libraries Reference Manual. Valid values: "CS_TRUE", "CS_FALSE". Default value: see Sybase documentation.
CS_VERSION Connection related. Should be specified before actual connection is made.	Describes the version of Client-Library behavior that the application expects. For more information see Sybase documentation. Valid values: "CS_VERSION_150" (15.0 behavior), "CS_VERSION_125" (12.5 behavior), "CS_VERSION_110" (11.0 behavior), "CS_VERSION_100" (10.0 behavior), "Detect" (SQLAPI++ automatically detects the maximum available version of behavior via the version of Client-Library), "Default" (SQLAPI++ tries to set 15.0 behavior; if it fails, SQLAPI++ tries to set 12.5 behavior; if it fails, SQLAPI++ tries to set 11.0 behavior and so on from the highest version to the lowest one until it succeeds). Default value: "Default".
CS_HAFAILOVER Connection related. Should be specified before actual connection is made.	Describes whether or not a connection uses HA failover. For information on CS_HAFAILOVER, see the Sybase Common Libraries Reference Manual. Valid values: "CS_TRUE", "TRUE", "1". Default value: none.
CS_LOGIN_TIMEOUT Connection related. Should be specified before actual connection is made.	For more information see Sybase documentation. Default value: empty.
CS_TIMEOUT Connection related. Should be specified before actual connection is made.	For more information see Sybase documentation. Default value: empty.
PreFetchRows Command related. Should be specified before command execution.	Forces SQLAPI++ Library to fetch rows in bulk, rather than retrieving records one by one. Valid values: String containing number of rows in the fetch buffer. Default value: "1".
ct_cursor Command related. Should be specified before command execution.	Instructs SQLAPI++ to use "ct_cursor" for current statement execution (as opposed to defaulting to "ct_command"). See Sybase documentation for more information on using cursors and their advantages and limitations. Valid values: a cursor name. See Sybase documentation on what constitutes a valid cursor name. Default value: not set. SQLAPI++ uses ct_command for statement execution.

For more details see SAConnection::setOption, SACommand::setOption, SAField::setOption, SAParam::setOption.

Getting native Sybase API

You can call client specific API functions which are not directly supported by SQLAPI++ Library. SAConnection::NativeAPI method returns a pointer to the set of native API functions available for Sybase . To use the database API directly you have to downcast this saAPI pointer to the appropriate type and use its implementation-specific members. The following table shows what type cast you have to make and what additional header file you have to include to work with Sybase API.

Type casting	Additional include file
Cast the result to class sybAPI: saAPI *pResult = con.NativeAPI(); sybAPI *p_sybAPI = (sybAPI *)pResult;	#include <sybAPI.h>

To get more information about DBMS API functions see this DBMS specific documentation. 

For more details see SAConnection::NativeAPI.

Getting native Sybase connection related handles

You have to use native API handles when you want to call specific Sybase API functions which are not directly supported by the Library. API functions usually need to receive one or more active handles as a parameter(s). SAConnection::NativeHandles method returns a pointer to the set of native API connection related handles. To use API handles directly you have to downcast saConnectionHandles pointer to the appropriate type and use its implementation-specific members. The following table shows what type cast you have to make and what additional header file you have to include to work with specific Sybase API.

Type casting

Cast the result to class sybConnectionHandles: #include <sybAPI.h> saConnectionHandles *pResult = con.NativeHandles(); sybConnectionHandles *p_sybCH =                                 (sybConnectionHandles *)pResult; Available handles: CS_CONNECTION *m_connection;

To get more information about DBMS API functions and handles see this DBMS specific documentation. 

For more details see SAConnection::NativeHandles.

Getting native Sybase command related handles

You have to use native API handles when you want to call specific Sybase API functions which are not directly supported by the Library. API functions usually need to receive one or more active handles as a parameter(s). SACommand::NativeHandles method returns a pointer to the set of native API command related handles. To use API handles directly you have to downcast saCommandHandles pointer to the appropriate type and use its implementation-specific members. The following table shows what type cast you have to make and what additional header file you have to include to work with specific Sybase API.

Type casting

Cast the result to class sybCommandHandles: #include <sybAPI.h> saCommandHandles *pResult = cmd.NativeHandles(); sybCommandHandles *p_sybCH =                                 (sybCommandHandles *)pResult; Available handles: CS_COMMAND *m_command;

To get more information about DBMS API functions and handles see this DBMS specific documentation. 

For more details see SACommand::NativeHandles.

Error handling

When an error occurs inside SQLAPI++ Library it throws an exception of type SAException. SAException::ErrPos method gets an error position in SQL statement. In Sybase server SAException::ErrPos method returns the number of line within SQL statement where error occurred.

For more details see How To - Error handling, SAException object.

Special header files - Compile time

The header files are in the include subdirectory of SQLAPI++ distributions:
#include <SQLAPI.h> - main header, should be used whenever SQLAPI++ is used.
#include <sybAPI.h> - Sybase , should be included if direct Open Client calls are required.

For more details see Online Documentation - Instructions for Compiling and Linking Applications with SQLAPI++ 

Problems and Questions

If you haven't found the answer to you questions or have some problems on using the Library, please, send e-mail to howto@sqlapi.com.