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 SACommand |
| SAConnection |
| SAException |
| SAField |
| SAParam |
| SAString |
| SADateTime |
| SANumeric |
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| Enums and Typedefs |
Server Specific Guide
SQLBase
SQLAPI++ allows to work with a number of SQL database servers. It provides common mechanisms to access database, and as a general rule they work for any database server. But each server has some specific features which a developer has to know in order to leverage server's unique features and avoid potential errors.
This page collects all specific information that concerns working with SQLBase server using SQLAPI++ Library. Full information about using SQLAPI++ see in How To and Online Documentation.
Available topics:
Working with Long or Lob(CLob, BLob) data
Connection, command, parameter and field options
Getting native SQLBase connection related handles
Getting native SQLBase command related handles
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 SQLBase 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. The database name as it
is specified in SQL.INI file.
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_SQLBase_Client SQLBase 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_SQLBase_Client constant before.
The SQLAPI++ Library requires CAPI version 6.x 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 SQLBase server in the following way:
SA_ReadUncommitted = SQLILRL ('RL')
SA_ReadCommitted = SQLILCS ('CS')
SA_RepeatableRead = SQLILRR ('RR')
SA_Serializable = SQLILRO ('RO')
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 <= > LONG VARCHAR
SA_dtLongChar <= > LONG VARCHAR
SA_dtBLob = > LONG VARCHAR
SA_dtCLob => LONG VARCHAR
For more details see How To - Working with Long or Lob(CLob, BLob) data
Returning output parameters
If SQLBase stored procedure returns only one row of output parameters (the most common case), you can get output parameters' values immediately after calling SACommand::Execute using appropriate SAParam objects.
In SQLBase stored procedures can also return several rows of output parameters. In this case SQLBase returns them as a result set and you can fetch them row by row using SACommand::FetchNext method after calling SACommand::Execute method.
For more details see SACommand::Execute, SAParam object, How To - Returning Output Parameters.
Cancelling queries
Using SACommand::Cancel method you can cancel the following types of processing on a statement:
- A function running asynchronously on the statement.
- A function running on the statement on another thread.
SQLAPI++ calls sqlcan function to cancel a query. To get more details see sqlcan function description in SQLBase documentation.
For more details see SACommand::Cancel.
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 SQLBase:
|
Option name / Scope |
Description |
|
SQLPPCX Command related |
Controls cursor-context preservation. For more
information see SQLBase documentation. |
|
StoredObject Command related |
If you call stored command you can set this option to
"Command" value. It allows SQLAPI++ to optimize stored command
execution. Valid values: "Procedure" and "Command". |
For more details see SAConnection::setOption, SACommand::setOption, SAField::setOption, SAParam::setOption.
Getting native SQLBase 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 SQLBase . 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 SQLBase API. Note that using appropriate type casting depends on an API version (that generally mean that you have to explicitly check client version before casting, see SAConnection::ClientVersion method).
|
DBMS client |
Type casting |
Additional |
|
SQLBase 6 |
Cast the result to class sb6API: saAPI *pResult = con.NativeAPI(); |
#include <sbAPI.h> |
|
SQLBase 7 |
Cast the result to class sb7API: saAPI *pResult = con.NativeAPI(); |
#include <sbAPI.h> |
To get more information about DBMS API functions see this DBMS specific documentation.
For more details see SAConnection::NativeAPI.
Getting native SQLBase connection related handles
You have to use native API handles when you want to call specific SQLBase 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 SQLBase API. Note that using appropriate type casting depends on an API version (that generally mean that you have to explicitly check client version before casting, see SAConnection::ClientVersion method).
|
DBMS client |
Type casting |
|
SQLBase 6 |
Cast the result to class sb6ConnectionHandles: #include <sbAPI.h> saConnectionHandles *pResult = con.NativeHandles(); Available handles:
|
|
SQLBase 7 |
Cast the result to class sb7ConnectionHandles: #include <sbAPI.h> saConnectionHandles *pResult = con.NativeHandles(); Available handles:
|
To get more information about DBMS API functions and handles see this DBMS specific documentation.
For more details see SAConnection::NativeHandles.
Getting native SQLBase command related handles
You have to use native API handles when you want to call specific SQLBase 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 SQLBase API.
|
Type casting |
|
Cast the result to class sbCommandHandles: #include <sbAPI.h> saCommandHandles *pResult = cmd.NativeHandles(); Available handles:
|
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 SQLBase server SAException::ErrPos method returns character position of the syntax error within an SQL statement. The first character is position 0.
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 <sbAPI.h> - SQLBase
, should be included if direct CAPI 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.