SQLBase Guide

SQLAPI++ allows to seamlessly work with a variety of SQL database servers. It provides unified API to access any database, keeping your code portable. 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.

For complete information on using SQLAPI++ check out Getting Started and Documentation. This guide covers specific information related to working with SQLBase server using SQLAPI++ library in the following areas:

Connecting to a database

To connect to a database you need to initialize a connection object. A connection object is represented by SAConnection class.

Minimum Version
SQLAPI++ library requires CAPI version 6.x or higher.

After the connection is created you need to call SAConnection::Connect method to establish connection with SQLBase server:

void Connect(
    const SAString &sDBString,
    const SAString &sUserID, 
    const SAString &sPassword, 
    SAClient_t eSAClient = SA_Client_NotSpecified);
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 eSAClient parameter is omitted. You can use this default value only if you have SAConnection::setAPI method with SAPI object initialized with SA_SQLBase_Client constant before

For more details see Getting Started - Connect to Database, 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 in the following way:

SA_ReadUncommittedSQLILRL ('RL')
SA_ReadCommittedSQLILCS ('CS')
SA_RepeatableReadSQLILRR ('RR')
SA_SerializableSQLILRO ('RO')

In addition to the SQL-92 levels, if you specify 'snapshot' isolation level, it will be mapped as: SA_Snapshot SQLILRO ('RO').

For more details see SAConnection::setIsolationLevel.

Working with Long or Lob (CLob, BLob) data

When fetching data SQLAPI++ detects data types of the columns in the result set and maps those types to internal library types. The mapping determines which native APIs the library will use for fetching LOB data.

The table below shows how SQLAPI++ maps SQLBase server data types to Long/Lob library types:

LONG BINARYSA_dtLongBinary
LONG VAR GRAPHICSA_dtLongBinary
LONG VARCHARSA_dtLongChar
CHAR > 254SA_dtLongChar
VARCHAR > 254SA_dtLongChar

When binding input data from your program the reverse mapping is taking place. The SQLAPI++ data type you use for input markers determines what native API program types will be used for sending Long/Lob data to the server.

The table below shows how SQLAPI++ maps its internal library types to SQLBase API data types:
SA_dtLongBinarySQLPLBI (long binary buffer)
SA_dtLongCharSQLPLON (long text string)
SA_dtBLobSQLPLBI (long binary buffer)
SA_dtCLobSQLPLON (long text string)

For additional information see Getting Started - Handle Long/CLob/BLob.

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.

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 additional information see SACommand::Execute, SAParam object, Getting Started - Get Output Parameters.

Cancelling queries

Using SACommand::Cancel method you can cancel the following types of processing on a statement:

  • function running asynchronously on the statement
  • 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 native SQLBase documentation.

For additional information see SACommand::Cancel.

Connection, command, parameter and field options

Server specific options can be applied at the API, connection, command, parameter or field levels.

We recommend you specify each option at the appropriate level, although it is possible to specify them at the parent object level as well. In that case the option affects all the child objects.

API level options must be specified in SAPI object. If an internal SAPI object is used for the DBMS API initialization (implicit DBMS API initialization, see SAConnection::Connect method) the related DBMS specific options are taken from the initial connection object.

Connection level options may be specified in either SAPI object or SAConnection object. If specified in SAPI object an option affects all connections on that API.

Command level options may be specified in SAPI object, SAConnection object or SACommand object. If specified in a parent object an option affects all commands on that SAPI or SAConnection object.

Parameter level options may be specified in SAPI object, SAConnection object, SACommand object or SAParam object. If specified in a parent object an option affects all parameters on that SAPI, SAConnection or SACommand object.

Field related options may be specified in SAPI object, SAConnection object, SACommand object or SAField object. If specified in a parent object an option affects all fields on that SAPI , SAConnection or SACommand object.

Specific options applicable to SQLBase:

SQLBASE.LIBS
Api Scope
Forces SQLAPI++ Library to use specified SQLBase client library.
Valid values: Any valid SQLBase client library name list. Names separated by ';' on Windows or ':' on other operating systems.
Default value:
  • Windows – "sqlwntm.dll"
  • Linux – "libsqlbapl.so"
SQLPPCX
Command Scope
Controls cursor-context preservation. For more information see SQLBase documentation.
Valid values: "off", "on"
Default value: see SQLBase documentation.
StoredObject
Command Scope
If you call stored command you can set this option to "Command" value. It allows SQLAPI++ to optimize stored command execution.
Valid values: "Procedure", "Command"
Default value: "Procedure"
UseDynamicCursor
Scrollable
Command Scope
Configures SQLAPI++ to use SQLBase scrollable result set mode.
Valid values: "True", "1"
Default value: "False"
SQLBaseUseDoubleForDecimal
Command Scope
Configures SQLAPI++ to use SA_dtDouble type for SQLBase DECIMAL(x,y) data type.
Valid values: "True", "1"
Default value: "False"

For additional information see SAOptions::setOption.

Using 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 IsaAPI pointer to the appropriate type and use its implementation-specific members. The following example 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 (that generally mean that you have to explicitly check client version before casting, see SAConnection::ClientVersion method).

To use native API you need to add SQLBase specific #include and cast the result of SAConnection::NativeAPI to class sbAPI:

#include "sbAPI.h"

IsaAPI *pApi = con.NativeAPI();
sbAPI *pNativeAPI = (sbAPI *)pApi;

To get more information about SQLBase API functions see SQLBase documentation.

For additional information 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 parameters. 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.

To access native connection handles you need to add SQLBase specific #include and cast the result to class sb7ConnectionHandles:

#include "sbAPI.h"

saConnectionHandles *pHandles = con.NativeHandles();
sb7ConnectionHandles *pNativeHandles = (sb7ConnectionHandles*)pHandles;

Note that appropriate type casting depends on an SQLBase API version. That generally mean that you have to explicitly check client version before casting, see SAConnection::ClientVersion method. If you are using older CAPI v6 client library, you need to cast to sb6ConnectionHandles, as connection handles are different in version 6:

#include "sbAPI.h"

saConnectionHandles *pHandles = con.NativeHandles();
sb6ConnectionHandles *pNativeHandles = (sb6ConnectionHandles*)pHandles;

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

For additional information 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 parameters. 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.

To access native command handles you need to add SQLBase specific #include and cast the result to class sbCommandHandles:

#include "sbAPI.h"

saCommandHandles *pHandles = cmd.NativeHandles();
sbCommandHandles *pNativeHandles = (sbCommandHandles*)pHandles;

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

For additional information see SACommand::NativeHandles.

Error handling

When an error occurs when executing a SQL statement SQLAPI++ library throws an exception of type SAException and SAException::ErrPos method returns error position in the SQL statement.

In SQLBase SAException::ErrPos method returns character position of the syntax error within an SQL statement. The first character is position 0.

For additional information see Getting Started - Error Handling, SAException object.