<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <HTML ><HEAD ><TITLE >Alter data of a column</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.7"><LINK REL="HOME" TITLE="The hk_classes programmer's tutorial" HREF="index.html"><LINK REL="PREVIOUS" TITLE="Show data of a column" HREF="chapter4.html"><LINK REL="NEXT" TITLE="Add a row" HREF="chapter6.html"><META HTTP-EQUIV="Content-Style-Type" CONTENT="text/css"><LINK REL="stylesheet" HREF="common/kde-common.css" TYPE="text/css"><META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1"><META HTTP-EQUIV="Content-Language" CONTENT="en"><LINK REL="stylesheet" HREF="common/kde-localised.css" TYPE="text/css" TITLE="KDE-English"><LINK REL="stylesheet" HREF="common/kde-default.css" TYPE="text/css" TITLE="KDE-Default"></HEAD ><BODY CLASS="CHAPTER" BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#AA0000" VLINK="#AA0055" ALINK="#AA0000" STYLE="font-family: sans-serif;" ><DIV CLASS="logoheader" ><A HREF="http://www.kde.org/" ></A ></DIV ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >The hk_classes programmer's tutorial</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="chapter4.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="chapter6.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="CHAPTER" ><H1 ><A NAME="CHAPTER5" ></A >Chapter 5. Alter data of a column</H1 ><P >We alter now the data of the column. Just give the new value as a parameter to the method hk_column::set_asstring().</P ><P > <DIV CLASS="EXAMPLE" ><HR><A NAME="AEN91" ></A ><P ><B >Example 5-1. Alter data of a column</B ></P ><TABLE BORDER="0" BGCOLOR="#E0E0E0" WIDTH="100%" ><TR ><TD ><PRE CLASS="PROGRAMLISTING" > 1 #include <hk_classes.h> 2 #include <iostream> 3 int main() 4 { 5 hk_drivermanager* mydrivermanager = new hk_drivermanager(); 6 if (mydrivermanager==NULL) {cout <<"error creating mydrivermanager"<<endl;exit(1);} 7 hk_connection* myconnection = mydrivermanager->new_connection("mysql"); 8 if (myconnection==NULL) {cout <<"error creating myconnection"<<endl;exit(1);} 9 myconnection->set_host("localhost"); 10 myconnection->set_user("root"); 11 myconnection->set_password("mypasswd"); 12 myconnection->connect(); 13 14 hk_database* mydatabase=myconnection->new_database("exampledb"); 15 if (mydatabase==NULL) {cout <<"error creating mydatabase"<<endl;exit(1);} 16 hk_datasource* mydatasource= mydatabase->new_table("authors"); 17 if (mydatasource==NULL) {cout <<"error creating mydatasource"<<endl;exit(1);} 18 mydatasource->enable(); 19 20 hk_column* mycolumn = mydatasource->column_by_name("name"); 21 if (mycolumn==NULL) {cout <<"error getting column"<<endl;exit(1);} 22 <FONT COLOR="RED" >mycolumn->set_asstring("my new data");</FONT > 23 <FONT COLOR="RED" >mydatasource->store_changed_data();</FONT > 24 delete mydrivermanager; 25 }</PRE ></TD ></TR ></TABLE ><HR></DIV ></P ><P >The method mydatasource->store_changed_data(); will store the changes. The data will also be stored when you move the rowselector to another row (hk_datasource::goto_row()) or when you disable the datasource (hk_datasource::disable()).</P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="chapter4.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="chapter6.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >Show data of a column</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" > </TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >Add a row</TD ></TR ></TABLE ></DIV ></BODY ></HTML >