With in Release 3.6 and higher you can do Full Outer Join
As in the example
Attached here the used sample data
And the SQL query as below:
select t1.account_id, t1.contract_no, t2.contract_no as t2contract_no, t2.sales_no from S1.Table02 as t2 FULL OUTER JOIN S1.Table01 as t1 on t2.contract_no = t1.contract_no
Note: Columns names should be unique as you can see here for "t2.contract_no" we added and alias "t2contract_no"
The expected output: