/**
* Method declaration
*
*
* @return
*
* @throws Exception
*/
public bool findFirst()
{
if (iIndex == null)
{
iIndex = tTable.getPrimaryIndex();
}
if (eStart == null)
{
nCurrent = iIndex.first();
}
else
{
int type = eStart.getArg().getDataType();
object o = eStart.getArg2().getValue(type);
nCurrent = iIndex.findFirst(o, eStart.getType());
}
while (nCurrent != null)
{
oCurrentData = nCurrent.getData();
if (!test(eEnd))
{
break;
}
if (test(eAnd))
{
return(true);
}
nCurrent = iIndex.next(nCurrent);
}
oCurrentData = oEmptyData;
if (bOuterJoin)
{
return(true);
}
return(false);
}
/**
* Method declaration
*
*
* @param e
*
* @throws Exception
*/
public void setCondition(Expression e)
{
int type = e.getType();
Expression e1 = e.getArg();
Expression e2 = e.getArg2();
if (type == Expression.AND)
{
setCondition(e1);
setCondition(e2);
return;
}
int candidate;
switch (type)
{
case Expression.NOT_EQUAL:
case Expression.LIKE: // todo: maybe use index
case Expression.IN:
candidate = 0;
break;
case Expression.EQUAL:
candidate = 1;
break;
case Expression.BIGGER:
case Expression.BIGGER_EQUAL:
candidate = 2;
break;
case Expression.SMALLER:
case Expression.SMALLER_EQUAL:
candidate = 3;
break;
default:
// not a condition so forget it
return;
}
if (e1.getFilter() == this)
{
// ok include this
}
else if (e2.getFilter() == this && candidate != 0)
{
// swap and try again to allow index usage
e.swapCondition();
setCondition(e);
return;
}
else
{
// unrelated: don't include
return;
}
Trace.assert(e1.getFilter() == this, "setCondition");
if (!e2.isResolved())
{
return;
}
if (candidate == 0)
{
addAndCondition(e);
return;
}
int i = e1.getColumnNr();
Index index = tTable.getIndexForColumn(i);
if (index == null || (iIndex != index && iIndex != null))
{
// no index or already another index is used
addAndCondition(e);
return;
}
iIndex = index;
if (candidate == 1)
{
// candidate for both start & end
if (eStart != null || eEnd != null)
{
addAndCondition(e);
return;
}
eStart = new Expression(e);
eEnd = eStart;
}
else if (candidate == 2)
{
// candidate for start
if (eStart != null)
{
addAndCondition(e);
return;
}
eStart = new Expression(e);
}
else if (candidate == 3)
{
// candidate for end
if (eEnd != null)
{
addAndCondition(e);
return;
}
eEnd = new Expression(e);
}
e.setTrue();
}
/**
* Method declaration
*
*
* @param e
*
* @throws Exception
*/
public void setCondition(Expression e)
{
int type = e.getType();
Expression e1 = e.getArg();
Expression e2 = e.getArg2();
if (type == Expression.AND)
{
setCondition(e1);
setCondition(e2);
return;
}
int candidate;
switch (type)
{
case Expression.NOT_EQUAL:
case Expression.LIKE: // todo: maybe use index
case Expression.IN:
candidate = 0;
break;
case Expression.EQUAL:
candidate = 1;
break;
case Expression.BIGGER:
case Expression.BIGGER_EQUAL:
candidate = 2;
break;
case Expression.SMALLER:
case Expression.SMALLER_EQUAL:
candidate = 3;
break;
default:
// not a condition so forget it
return;
}
if (e1.getFilter() == this)
{
// ok include this
}
else if (e2.getFilter() == this && candidate != 0)
{
// swap and try again to allow index usage
e.swapCondition();
setCondition(e);
return;
}
else
{
// unrelated: don't include
return;
}
Trace.assert(e1.getFilter() == this, "setCondition");
if (!e2.isResolved())
{
return;
}
if (candidate == 0)
{
addAndCondition(e);
return;
}
int i = e1.getColumnNr();
Index index = tTable.getIndexForColumn(i);
if (index == null || (iIndex != index && iIndex != null))
{
// no index or already another index is used
addAndCondition(e);
return;
}
iIndex = index;
if (candidate == 1)
{
// candidate for both start & end
if (eStart != null || eEnd != null)
{
addAndCondition(e);
return;
}
eStart = new Expression(e);
eEnd = eStart;
}
else if (candidate == 2)
{
// candidate for start
if (eStart != null)
{
addAndCondition(e);
return;
}
eStart = new Expression(e);
}
else if (candidate == 3)
{
// candidate for end
if (eEnd != null)
{
addAndCondition(e);
return;
}
eEnd = new Expression(e);
}
e.setTrue();
}
