Oracle recursive query

1, from the top down query

Use start with a= ' starting ID ' connect by prior a= B

A is a subkey and B is the parent.

Select F_ca_code,f_ca_parentcode,level from with='0'  by=

Query Result:

Where level is the Oracle built-in function

If you join a query, you need to include it in front of start with:

Select F_ca_code,f_ca_parentcode,level fromwherelevel=3with  ='0'by=

Query Result:

2, from the bottom up query

Use start with a= ' starting ID ' connect by prior b= a

A is a subkey and B is the parent.

Select F_ca_code, level from with f_ca_code='10011'by   prior  =F_ca_code

Query Result:

Where level is the Oracle built-in function

If you join a query, you need to include it in front of start with:

Select F_ca_code,level fromwherelevel=2 with F_ca_code = ' 10011 '  by  Prior  =F_ca_code

Query Result:

Oracle recursive query