SQL Advanced Query Tips (two joins in the same table, self-contained joins, unequal joins)

Master these, it's more advanced.

Using the same Table twice

such as the Branch field in the following query

SELECTa.account_id, e.emp_id, B_a.name open_branch, B_e.name emp_branch fromAccount asAINNER JOINBranch asB_a ona.open_branch_id=b_a.branch_idINNER JOINEmployee asE ona.open_emp_id=e.emp_idINNER JOINBranch B_e one.assigned_branch_id=b_e.branch_idWHEREA.product_cd= 'CHK';

Self-Joins

Because the employee has self-quoted superiors, there is a possibility that there is a case in Django example.

SELECT  from  as INNER JOIN  as  on = e_mgr.emp_id;

Non-equi-joins

In the on condition of the join statement, you don't have to use the equals sign or

SELECT ' VS '  from  as INNER JOIN  as  on < WHERE = ' Teller '  and = ' Teller ';

SQL advanced Query Tips (two joins in the same table, self-contained joins, unequal joins)