interbase.html

能够连接各种数据库的API

            isc_tpb_rec_version<BR><STRONG> SA_ReadCommitted</STRONG> = isc_tpb_read_committed,  
             isc_tpb_no_rec_version<BR><STRONG> SA_RepeatableRead</STRONG> =    
            isc_tpb_consistency<BR><STRONG> SA_Serializable</STRONG> =   
            isc_tpb_concurrency</P>
            <P>For more details see <A 
            href="../OnLineDoc/Connection_setIsolationLevel.html">SAConnection::setIsolationLevel</A>.</P>
            <P>&nbsp;</P>
            
            <H3><A 
            name="Working with Long or Lob(CLob, BLob) data">Working with Long or Lob(CLob, 
            BLob) data</A>    </H3>
            <P> 
            SQLAPI++ supports four types for working with 
            Long or Lob(CLob, BLob) data:</P>
            <P>
            <TABLE border=1 cellPadding=1 cellSpacing=1 style="WIDTH: 100%" 
            width=100%>
                
                <TR bgColor=navy>
                    <TD><FONT color=white 
                        style="BACKGROUND-COLOR: #000080">Name</FONT></TD>
                    <TD><FONT color=white 
                        style="BACKGROUND-COLOR: #000080">C 
                        enum constant</FONT></TD>
                </TR>
                <TR>
                    <TD>LongBinary</TD>
                    <TD>SA_dtLongBinary</TD>
                </TR>
                <TR>
                    <TD>LongChar</TD>
                    <TD>SA_dtLongChar</TD>
                </TR>
                <TR>
                    <TD>BLob (Binary Large object)</TD>
                    <TD>SA_dtBLob</TD>
                </TR>
                <TR>
                    <TD>CLob (Character Large object)</TD>
                    <TD>SA_dtCLob</TD>
                </TR></TABLE></P>
            <P>The table below shows how SQLAPI++ data 
            types correspond with servers original data types:</P>
            <P><EM>SA_dtLongBinary</EM> &lt;= &gt; BLOB,  subtype 0<BR><EM>SA_dtLongChar</EM> 
            &lt;= &gt; 
            BLOB,  subtype 1<BR 
            ><EM>SA_dtBLob</EM> = &gt; BLOB,  subtype 
            0<BR><EM>SA_dtCLob 
            </EM>=&gt; BLOB, subtype 1</EM></P>
            <P>
            For more details see <A href="../HowTo/blobs.html">How To - Working with Long or Lob(CLob, BLob) data</A></P>
            <P>&nbsp;</P>
            
            <H3><A 
            name="Returning output parameters">Returning output 
            parameters</A>  </H3>
            <p>If <STRONG>InterBase</STRONG>
            stored procedure returns only one row of 
            output parameters (the most common case), you can get output 
            parameters' values immediately after calling <A href="../OnLineDoc/Command_Execute.html" >SACommand::Execute</A>
            using 
            appropriate <A href="../OnLineDoc/Param.html" >SAParam</A> 
            objects.</p>
            <P>In <STRONG>InterBase</STRONG> 
              stored procedures can also 
            return several rows of output parameters. In this case you should perform 
            a select from a procedure to return them as result set.</P>
            <P>For more details see <A 
            href="../OnLineDoc/Command_Execute.html" >SACommand::Execute</A>, 
            <A href="../OnLineDoc/Param_Usage.html" >SAParam 
            object</A>, <A 
            href="../HowTo/return_param.html" >How To - Returning Output Parameters</A>.</P>
            <P>&nbsp;</P>
            
            <H3><A name="Cancelling queries">Cancelling 
            queries</A> </H3>
            <P><STRONG>InterBase</STRONG> does not support cancelling 
            queries.</P>
            <P>&nbsp;</P>
            
            <H3><A 
            name="Connection and command options">Connection, command, parameter and field 
            options</A>   </H3>
            <P>A server specific option can relate to a 
            connection, command,&nbsp; 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. </P>
            <P>A connection related option must be specified 
            in a&nbsp; <A href="../OnLineDoc/Connection.html">SAConnection</A> 
            object. </P>
            <P>A command related option may be specified in 
            either <A href="../OnLineDoc/Connection.html">SAConnection</A>
            object or <A href="../OnLineDoc/Command.html">SACommand</A>
            object. If it is specified 
            in <A href="../OnLineDoc/Connection.html">SAConnection</A> 
            object it affects all 
            the commands on that connection. </P>
            <P>A parameter related option may be specified in 
            <A href="../OnLineDoc/Connection.html">SAConnection</A>
            object, <A href="../OnLineDoc/Command.html">SACommand</A>
            object or <A href="../OnLineDoc/Param.html">SAParam</A>
            object. If it is specified in 
            <A href="../OnLineDoc/Connection.html">SAConnection</A>
            object it affects all 
            the commands and therefore all the parameters on that connection. If 
            it is specified in <A href="../OnLineDoc/Command.html">SACommand</A> 
            object it affects all the 
            parameters on that command. </P>
            <P>A field related option may be specified in 
            <A href="../OnLineDoc/Connection.html">SAConnection</A>
            object, <A href="../OnLineDoc/Command.html">SACommand</A>
            object or <A href="../OnLineDoc/Field.html">SAField</A>
            object. If it is specified in 
            <A href="../OnLineDoc/Connection.html">SAConnection</A>
            object it affects all 
            the commands and therefore all the fields on that connection. If it 
            is specified in <A href="../OnLineDoc/Command.html">SACommand</A> 
            object it affects all the 
            fields on that command. </P>
            <P>Specific options for <STRONG> InterBase</STRONG>:</P>
            <P>
            <TABLE border=1 cellPadding=5 width=100%>
                <TBODY>
                <TR bgColor=#000094>
                    <TD width=17%>
                        <P><STRONG><FONT color=white face="">Option name / Scope</FONT>&nbsp; 
                        </STRONG></P></TD>
                    <TD>
                        <P><STRONG><FONT color=white face=""> Description</FONT> 
                        </STRONG></P></TD></TR>
                <TR>
                    <TD><STRONG><STRONG>
                        <P align=center><STRONG><STRONG>
                        <STRONG><STRONG>isc_dpb_lc_ctype</STRONG></STRONG></STRONG> 
                        </STRONG></P></STRONG> 
                        </STRONG>
                        <P align=center>Connection related. 
                        Should be specified before actual connection is 
                        made.</P></TD>
                    <TD>
                        <P>Specifies the character set to 
                        be utilized. For more information see InterBase 
                        documentation.<BR>   
                                
                            </P>
                        <P><EM>Valid values</EM>: String containing 
                        character set name, see InterBase documentation.<BR 
                        ><EM>Default 
                        value</EM>: see InterBase documentation.</P></TD></TR>
                <TR>
                    <TD>
                        <P align=center><STRONG><STRONG>
                        <STRONG><STRONG>isc_dpb_sql_role_name</STRONG></STRONG></STRONG> 
                        </STRONG></P>
                        <P align=center><STRONG><STRONG>
                        <STRONG><STRONG></STRONG></STRONG></STRONG> 
                        </STRONG>Connection 
                        related. Should be specified before actual connection is 
                        made.&nbsp;</P>
                    <TD>
                        <P>Declares role name that should 
                        used for connection. For more information see InterBase 
                        documentation.<BR>   
                                
                            </P>
                        <P><EM>Valid values</EM>: see InterBase 
                        documentation.<BR><EM>Default value</EM>: 
                        see InterBase documentation.</P>
                <TR>
                    <TD><STRONG><STRONG>
                        <P><STRONG>isc_dpb_num_buffers</STRONG></P></STRONG> 
                        </STRONG>
                        <P align=center>Connection related. 
                        Should be specified before actual connection is 
                        made.<STRONG><STRONG><STRONG></STRONG></STRONG> 
                        </STRONG></P></TD>
                    <TD>
                        <P>Declares the number of database cache buffers to 
                        allocate for use with the database. For more information 
                        see InterBase documentation.<BR>  
                           </P>
                        <P><EM>Valid values</EM>: 10-255, see InterBase 
                        documentation.<BR><EM>Default value</EM>: 
                        75, see InterBase documentation.</P></TD></TR>
                <TR>
                    <TD><STRONG><STRONG>
                        <P align=center><STRONG>CommitRetaining</STRONG></P></STRONG> 
                        </STRONG>
                        <P align=center>Connection related. 
                        Should be specified before issuing a commit.<STRONG><STRONG><STRONG></STRONG></STRONG> 
                        </STRONG></P></TD>
                    <TD>
                        <P>Determines which function (<EM 
                        >isc_commit_transaction()</EM> or <EM 
                        >isc_commit_retaining()</EM>) 
                        SQLAPI++ calls&nbsp; to commit transactions.<BR 
                        ><EM>isc_commit_transaction()</EM> writes transaction 
                        changes permanently to a database, closes the result set 
                        associated with the transaction, and frees system 
                        resources assigned to the transaction for other uses. 
                        Active result sets are not preserved.<BR><EM>isc_commit_retaining()</EM> 
                        writes all pending changes to the database, ends the 
                        current transaction without closing its record stream 
                        and cursors and without freeing its system resources, 
                        then starts a new transaction and assigns the existing 
                        record streams and system resources to the new 
                        transaction. Active result sets are preserved. <BR 
                        >For more information see InterBase 
                        documentation (<EM>isc_commit_retaining()</EM> and <EM>isc_commit_transaction()</EM> functions). <BR>  
                        <BR> 
                        <EM>Valid 
                        values</EM>: &quot;true&quot; to 
                        force SQLAPI++ to call <EM>isc_commit_retaining()</EM> function, 
                        &quot;false&quot; to force SQLAPI++ to call <EM 
                        >isc_commit_transaction()</EM> 
                        function.<BR><EM>Default value</EM>: 
                        &quot;false&quot;. SQLAPI++ uses <EM>isc_commit_transaction()</EM>  
                         function by default.</P></TD></TR>
                <TR>
                    <TD>
                        <P align=center><STRONG>TPB_LockResolution</STRONG></P> 
                        <P align=center>Connection related. 
                        Should be specified before actual connection is 
                        made.
                        </P></TD>
                    <TD>
                        <P>Describes what happens if a transaction 
                        encounters an access conflict during a write 
                        operation (update and delete operations on 
                        existing rows).<BR>  
                           </P>
                        <P><EM>Valid values</EM>: &quot;isc_tpb_wait&quot; 
                        (specifies that the transaction should wait 
                        until locked resources are released; once the 
                        resources are released, the transaction retries 
                        its operation), 
                        &quot;isc_tpb_nowait&quot; (specifies that the 
                        transaction should return a lock conflict error 
                        without waiting for locks to be released).