sybase.html

通用的数据库中间库

                href="../OnLineDoc/Connection_setClient.html">SAConnection::setClient</A> 
                method with <STRONG>SA_Sybase_Client</STRONG> constant before.</LI> 
            </UL>     
                <P>The SQLAPI++ Library requires Open Client 
            version 10.0 or higher.</P>
            <P>For more details see <A 
            href="../HowTo/connect.html">How To - Connecting to databases</A>, <A 
            href="../OnLineDoc/Connection_Usage.html">SAConnection object</A>, <A 
            href="../OnLineDoc/Connection_Connect.html">SAConnection::Connect</A>.</P>
            <P>&nbsp;</P>
            <H3><A 
            name="Transaction isolation levels">Transaction isolation 
            levels</A>  </H3>
            <P>SQL-92 defines four isolation levels, all of 
            which are supported by SQLAPI++:</P>
            <UL>
                <LI>Read uncommitted (the lowest level where 
                transactions are isolated just enough to ensure that physically 
                corrupt data is not read) 
                <LI>Read committed 
                <LI>Repeatable read 
                <LI>Serializable (the highest level, where 
                transactions are completely isolated from one another)</LI></UL>
            <P>SQLAPI++ maps different isolation levels on 
            <STRONG>Sybase</STRONG> server in the following way:</P>
            <P>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <STRONG 
            >SA_ReadUncommitted</STRONG> = CS_OPT_LEVEL0 
  ('read 
            uncommitted')<BR><STRONG>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; SA_ReadCommitted</STRONG> = 
            CS_OPT_LEVEL1  
            ('read committed')<BR><STRONG>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; SA_RepeatableRead</STRONG> = CS_OPT_LEVEL2 ('repeatable  
            read')<BR><STRONG>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; SA_Serializable</STRONG> = 
            CS_OPT_LEVEL3  
            ('serializable')</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; IMAGE<BR><EM>SA_dtLongChar</EM> &lt;= &gt; TEXT<BR 
            ><EM>SA_dtBLob</EM> = &gt; 
            IMAGE<BR><EM>SA_dtCLob 
            </EM>=&gt; TEXT</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><STRONG>Sybase ASE</STRONG>
            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 <A 
            href="../OnLineDoc/Param_setParamDirType.html">SAParam::setParamDirType</A> 
            method for these parameters before command execution and set 
            parameter's direction type explicitly.<BR>You 
            shouldn't call this method for procedure status result code because 
            it is detected correctly (as SA_ParamReturn) by the Library.</p>
            <p>There is no need to call this method for 
            <STRONG>Sybase ASA</STRONG> because all 
            parameters are detected correctly automatically (including the 
            direction type).</p>
            <P>For more details see <A 
            href="../OnLineDoc/Param_setParamDirType.html">SAParam::setParamDirType</A>.</P>
            <P>       
                       
             In <STRONG>Sybase</STRONG> server 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 <A href="../OnLineDoc/Command_FetchNext.html" >SACommand::FetchNext</A> 
            method.</P>
            <P>SQLAPI++ Library automatically creates <A href="../OnLineDoc/Param.html" >SAParam</A> object to represent procedure 
            status return code. You can refer to this <A href="../OnLineDoc/Param.html" >SAParam</A> object using SQLAPI++ predefined 
            name <STRONG>&quot;RETURN_VALUE&quot;</STRONG>.</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>Sybase</STRONG> 
            does not support queries 
            cancelling.</P>
            <P>&nbsp;</P>
            <H3><A name="Connection and command options"><A 
            name="Connection and command options">Connection and command 
            options</A><A name="Connection and command options"></A></A> 
            </H3>
            <P>A server specific option can be related with 
            a command or with a connection. A connection related option must be 
            specified in a&nbsp; <A href="../OnLineDoc/Connection.html" >SAConnection</A>object. A command 
            related option may be specified in either <A href="../OnLineDoc/Connection.html" >SAConnection</A>object 
            or <A href="../OnLineDoc/Command_Usage.html" >SACommand</A> 
            object. </P>
            <P>Specific options for <STRONG>Sybase</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</FONT>&nbsp; </STRONG></P></TD>
                    <TD>
                        <P><STRONG><FONT 
                        color=white face="">Description</FONT> </STRONG></P></TD></TR>
                <TR>
                    <TD>
                    <STRONG>
                        CS_PACKETSIZE</STRONG>
                    <TD>Determines the packet size that Client-Library uses 
                        when sending Tabular Data Stream (TDS) packets. For more 
                        information see Sybase documentation.<BR><STRONG>Connection related.</STRONG> Should be 
                        specified before actual connection is made.<BR>Valid values: String containing 
                        packet size, see Sybase documentation.<BR>Default value: see Sybase documentation.
                <TR>
                    <TD>
                    <STRONG>
                        CS_APPNAME</STRONG>
                    <TD>Defines the application name that a connection will 
                        use when connecting to a 
                        server. For more information see Sybase 
                        documentation. <BR><STRONG>Connection related.</STRONG> Should be 
                        specified before actual connection is made.<BR 
                        >Valid values: see Sybase 
                        documentation. <BR 
                        >Default value: see 
                        Sybase documentation.
                <TR>
                    <TD>
                        <P align=center>
            <STRONG>CS_HOSTNAME</STRONG></P></TD>
                    <TD>
                        <P>Declares the name of the host 
                        machine, used when logging in to a server. For more 
                        information see Sybase documentation. <BR > <STRONG>Connection related.</STRONG> Should be 
                        specified before actual connection is made.
            <BR>Valid values: see Sybase 
                        documentation.<BR >   Default value: 
                        see Sybase documentation.</P></TD></TR>
             <TR>
                 <TD>  <STRONG><P align=center> 
                          <STRONG>PreFetchRows</STRONG></P></STRONG></TD>
                 <TD>
					<P>
                    Forces SQLAPI++ Library to fetch 
 
                    rows in bulk, rather than 
                        retrieving records one by one.
                    <BR>
                        <STRONG>Command 
                        related.</STRONG> Should be specified 
                        before command execution.<BR>Valid 
                        values: String containing number of rows