Working with Queries 2 in AX 2012 and Dynamics 365

public Query queryBuild()
{
Query q;
QueryRun qr;
QueryBuildDataSource qbd,qbd1;

q = new Query();

qbd = q.addDataSource(TableNum(CustTable));
qbd1 = qbd.addDataSource(TableNum(CustTrans));
qbd1.addLink(fieldNum(CustTable, CustAccount), fieldNum(CustTrans, CustAccount));

return q;
}

public Query queryBuildHeader()
{
Query q;
QueryRun qr;
QueryBuildDataSource qbd,qbd1;

q = new Query();

qbd = q.addDataSource(TableNum(CustTable));

return q;
}

==
Query q = this.queryBuildHeader();