Oracle SQL can do hierarchical queries since v2, using their proprietary CONNECT BY syntax. In their latest 11g release 2, they added recursive subquery factoring, also known as the recursive with ...

Does PostgreSQL have a pseudo-column like "LEVEL" in Oracle? If not, then how can we create a column similar to "LEVEL"?

I am trying and searching the way to get ALL last level children (leafs) from a node, in a hierchical query in Oracle 11g database. I have 2 tables: "Nodes" (A list of all nodes with their respec...

I'm using PostgreSQL 9.1 to query hierarchical tree-structured data, consisting of edges (or elements) with connections to nodes. The data are actually for stream networks, but I've abstracted the ...

Suppose that we have following tables create table Employee( 2 EMPNO NUMBER(3), 3 ENAME VARCHAR2(15 BYTE), 4 HIREDATE DATE, 5 ORIG_SALARY NUMBER(6), 6 CURR_SALARY NUMBER(6), 7 REGION VARCHAR...

I have just run across this interesting article here, showing how to simulate wm_concat() or group_concat() in Oracle using a hierarchical query and window functions: SELECT deptno, LTRIM(MAX(SYS...