Query - how to i convert this queries code into sql statement

Hi Axapta developer,

I am new to axapta, i have a queries code like the follwong:

Void calculateDetails(CustTable _custTable)
{
TransDate startDate;
TransDate endDate;
Counter numOfAge;
CustTrans custTrans;
CustSettlement custSettlement;
custTransOpen custTransOpen;

QueryRun queryRun = new QueryRun(queryStr(CustTransCustSettlementCustTransOpen));
;
tmpAccountSum = null;
balanceDate = transactionDate;

queryRun.query().dataSourceTable(tableNum(CustTrans)).findRange(fieldNum(CustTrans, accountNum)).value(queryValue(_custTable.accountNum));
queryRun.query().dataSourceTable(tableNum(CustTrans)).findRange(fieldNum(CustTrans, transDate)).value(queryRange(dateNull(),transactionDate));
queryRun.query().dataSourceTable(tableNum(CustTrans)).findRange(fieldNum(CustTrans, closed)).value(SysQuery::valueEmptyString()+’,’+ queryRange(transactionDate, dateMax()));

queryRun.query().dataSourceTable(tableNum(CustSettlement)).findRange(fieldNum(CustSettlement,transDate)).value(queryRange(transactionDate + 1,dateMax()));

while (queryRun.next())
{
if (queryRun.changed(tableNum(CustTrans)))
{
custTrans = queryRun.get(tableNum(CustTrans));
custTrans.transactionPerDate(transactionDate);
if (!custTrans.invoice)
{
this.testPaymentForInvoice(transactionDate, custtrans);
}
balanceAge[1] += custTrans.remainAmountMST();
}

endDate = dateMax();
startDate = zeroDate + 1;

if (queryRun.changed(tableNum(CustSettlement)))
{
custSettlement = queryRun.get(tableNum(CustSettlement));
for (numOfAge=2; numOfAge <= dimof(balanceAge); numOfAge++)
{
startDate = startDateArray[numOfAge];
endDate = endDateArray[numOfAge];
if (!custSettlement.dueDate)
{
custSettlement.dueDate = custTransOpen::findRefId(custSettlement.transRecId).dueDate;
}

if(this.dateOkSettlement(custSettlement, startDate, endDate))
{
tmpAccountSum.accountNum = _custTable.accountNum;
this.placeTransInColumns(custTrans, custSettlement.settleAmountMST - custSettlement.exchAdjustment, numOfAge, custSettlement.dueDate);
break;
}
}
}

if (queryRun.changed(tableNum(custTransOpen)))
{
custTransOpen = queryRun.get(tableNum(custTransOpen));
for (numOfAge=2; numOfAge <= dimof(balanceAge); numOfAge++)
{
startDate = startDateArray[numOfAge];
endDate = endDateArray[numOfAge];
if (this.dateOkTransOpen(custTransOpen, startDate, endDate))
{
tmpAccountSum.accountNum = _custTable.accountNum;
this.placeTransInColumns(custTrans, custTransOpen.amountMST, numOfAge, custTransOpen.dueDate);
break;
}
}
}
}

How should i convert this code into the sql statement