The preferred method of looping through data or sets is the for-next-loop. In the example below a list box is populated from a collection of MySQL data records.
[codesyntax lang=”cpp”]
void dlgDe2::PopLb()
{
size_t iend = da.kjbill_read();
for (int ii=0; ii < iend; ii++)
{
lbxItems->Append(std::to_string(da.kjbilla[ii].id) + " " + da.kjbilla[ii].item);
}
}
[/codesyntax]
The definition for object da is below.
[codesyntax lang=”cpp”]
#include "bcswebtools_kjbill_io.h" bcswebtools_kjbill_io da;
[/codesyntax]
The method to read the data table is below.
[codesyntax lang=”cpp”]
size_t bcswebtools_kjbill_io::kjbill_read()
{
int ii = 0;
size_t numRecs = 0;
dbc.driver = get_driver_instance();
dbc.con = dbc.driver->connect(dbc.server, dbc.user, dbc.pwd);
dbc.con->setSchema(dbc.catalog);
dbc.stmt = dbc.con->createStatement();
string cmd;
cmd = "SELECT id,cnt,item,ltot,cost FROM kjbill order by item";
if (isel == 1)
{
cmd = "SELECT id,cnt,item,ltot,cost FROM kjbill where id = " + oneRec;
}
if (isel == 2)
{
cmd = "SELECT id,cnt,item,ltot,cost FROM kjbill order by id";
}
dbc.res = dbc.stmt->executeQuery(cmd.c_str());
numRecs = dbc.res->rowsCount();
if (numRecs < maxRecs)
{
while (dbc.res->next())
{
kjbilla[ii].id = dbc.res->getInt("id");
kjbilla[ii].cnt = dbc.res->getInt("cnt");
kjbilla[ii].item = dbc.res->getString("item");
kjbilla[ii].ltot = dbc.res->getDouble("ltot");
kjbilla[ii].cost = dbc.res->getDouble("cost");
ii++;
}
}
delete dbc.res;
delete dbc.stmt;
delete dbc.con;
return numRecs;
}
[/codesyntax]
Below is the discription for the records.
[codesyntax lang=”cpp”]
struct kjbill_area {
int id;
int cnt;
string item;
double ltot;
double cost;
dcost_area dca;
};
[/codesyntax]
Mr. Arch Brooks, Software Engineer, Brooks Computing Systems, LLC authored this article.