ODynasetMark Method

Applies To

ODynasetMark

Description

ODynasetMark constructor

Usage

ODynasetMark(void)

ODynasetMark(const ODynasetMark &othermark)

Arguments

othermark

another ODynasetMark object that you are copying

Remarks

These methods construct a new ODynasetMark instance.

The default constructor constructs an unopened ODynasetMark object. It cannot fail.

The copy constructor copies another ODynasetMark object. If that other ODynasetMark object is open - which means it contains a valid mark on a dynaset - that mark will be copied. The copy constructor can fail; check whether the new ODynasetMark is open after the constructor call.

There is no Open method for the ODynasetMark class. To get an open ODynasetMark, call either GetMark or GetLastModifiedMark.

Example

This example finds the employee with the lowest salary and then gives that person a big commission.

// open the employee database

ODatabase odb("ExampleDB", "scott", "tiger");

// open a dynaset on the employee's table

ODynaset odyn(odb, "select sal, comm from emp");

// the low employee mark

ODynasetMark lowmark; // default constructor. lowmark is not open

double lowsalary = 100000.;

// find the lowest salary

OField salf = odyn.GetField(0); // salary is the 0th field

odyn.MoveFirst();

while (!odyn.IsEOF())

{

if ((double) salf < lowsalary)

{ // the lowest we've seen yet

// get a mark. odyn.GetMark returns an open ODynasetMark

lowmark = odyn.GetMark();

lowsalary = (double) salf;

}

odyn.MoveNext();

}

if (lowmark.IsOpen())

{ // we found a lowest - give them a big commission

odyn.MoveToMark(lowmark);

odyn.StartEdit();

odyn.SetFieldValue("comm", 2000.0);

odyn.Update();

}