Ax中多表关联仅提供Inner Join/Outer Join/Exist join/Not Exist join,而么有union,可以通过Query来实现.

例如 Sql:

select ItemType,GoodsName from table1 where TransDate between g_DateB and g_DateE
union
select ItemType,GoodsName from table2 where TransDate between g_DateB and g_DateE

1 实现[ from table1 ]
    qbd = query.addDataSource(tableNum(table1));
2 实现[ select ItemType,GoodsName ]
    qbd.addSelectionField(fieldnum(table1,ItemType));
    qbd.addSelectionField(fieldnum(table1,GoodsName));
3 实现[ where TransDate between g_DateB and g_DateE ]
  qbd.addRange(fieldnum(table1,TransDate)).value(strfmt("%1..%2", g_DateB,g_DateE));
4 实现[ union ]
    query.queryType(QueryType::Union);
  
代码:
   Query query;
    QueryRun qr;
    QueryBuildDataSource qbd;
    QueryBuildDataSource qbd2;
    Table1 newTable;

    qbd = query.addDataSource(tableNum(table1));
    qbd.addSelectionField(fieldnum(table1,ItemType));
    qbd.addSelectionField(fieldnum(table1,GoodsName));
    qbd.addRange(fieldnum(table1,TransDate)).value(strfmt("%1..%2", g_DateB,g_DateE));

    qbd2 = query.addDataSource(tablenum(table2));
    qbd2.addSelectionField(fieldnum(table2,ItemType));
    qbd2.addSelectionField(fieldnum(table2,GoodsName));
    qbd2.addRange(fieldnum(table2,TransDate)).value(strfmt("%1..%2", g_DateB,g_DateE));

    qbd2.addRange(fieldnum(table2,RecId)).
            value(strfmt("((%1 > %2) || (%3 > %4) || (%5 > %6))",
            fieldstr(table2,Qty),queryValue(0),
            fieldstr(table2,Weight),queryValue(0),
            fieldstr(table2,Volume),queryValue(0)));// OR Condition

    query.queryType(QueryType::Union);
    qr = new QueryRun(query);
    while(qr.next())
    {
     newTable = qr.get(tableNum(table1));
     //do something...
  }