Query “join table A with table B and table A with table C”

//
Query query = new Query();
QueryBuildDataSource qbds,qbds1,qbds2;
qbds = query.addDataSource(tableNum(CustTable));
qbds1 = qbds.addDataSource(tableNum(CustTrans));
qbds2 = qbds1.addDataSource(tableNum(CustLedgerTransTypeMapping));
qbds1.addLink(fieldNum(CustTrans,AccountNum),fieldNum(CustTable,AccountNum));
qbds2.addLink(fieldNum(CustTrans,TransType),fieldNum(CustLedgerTransTypeMapping,CustSettleTransType));
info(query.toString());
------------------
static void Job20(Args _args)
{
Query q;
QueryRun qr;
QueryBuildDatasource qbds1, qbds2;
QueryBuildRange qbr;
LedgerTable _LedgerTable;
;
q = new Query();
qbds1 = q.addDataSource(tablenum(LedgerTable));
qbds2 = qbds1.addDataSource(tablenum(LedgerTrans));
qbds2.relations(TRUE); //this enforces a relationship between this datasource and its parent. Relationships defined in the Data Dictionary are used by default.
qbr = qbds1.addRange(fieldnum(LedgerTable,
AccountNum));
//qbr.value(SysQuery::value("10000")); //SysQuery object provides various static methods to assist in defining Query criteria. The SysQuery::value() method should always be used when defining a singular value for a range.
qr = new QueryRun(q);
while(qr.next())
{
//do something
info(_LedgerTable.AccountNum);

}
}