On Wed, Feb 1, 2012 at 3:27 PM, <brooks.glenn@xxxxxxxxxxx> wrote:
I'm not positive from your description, but it seems like the concept you are missing is that a single table can have several aliases in one SQL query, which makes it appear to be several different tables. Take a simple example: a "personnel" table with employees and supervisors. Find everyone with supervisor "Jones":
select name from personnel emp join personnel super on (emp.supervisor = super.name)
where super.name = 'Jones';
Even though it's one table, you can make it look like two tables.
Craig
Hello,So I am not very advanced in SQL, and after a week of wild SQL experimenting have finally reduced my thought process to a complete blank on this query...I have a list of organizations in table:organization and a one to many list of organizational partnerships in a second table (table:partners). The 'partners' table lists each organization id that belongs to each partnership.The partnership relationships are recursive in that each partner is an 'ego' to one or more 'alter' partners, and an alter to other 'ego' partners.So I havent been able to figure out a way to select business partners 'alter' organizations that are distinctly related to each 'ego' organization.
I'm not positive from your description, but it seems like the concept you are missing is that a single table can have several aliases in one SQL query, which makes it appear to be several different tables. Take a simple example: a "personnel" table with employees and supervisors. Find everyone with supervisor "Jones":
select name from personnel emp join personnel super on (emp.supervisor = super.name)
where super.name = 'Jones';
Even though it's one table, you can make it look like two tables.
Craig
I would like to create SQL output that looks like this:
self partner id business partner Org1 100 Org2 Org1 100 Org3 Org2 100 Org1 Org2 100 Org3 Org3 100 Org1 Org3 100 Org2
(The futher complexities are that every combination of partnerships and the life cycle of each partnership can be a many to many relation and each org may be partnered or opposed to other orgs, or a partnership may eventually turn sour resulting in the partnership being dissolved and the participants becoming competitors - its endless in this regard :<)I tried a many to many tables querying ego_org and alter_org, however each alter has the same ego elsewhere in the table, so the normanization is screwed up...so i finaly went back to a one to many model shown below:
table:org--------------------------------orgid org nameorg1 xyzorg2 abcorg3 blah blahorgx etcTable: partners---------------------------------------partnerid member_org100 org1100 org2101 org1101 org25102 org2102 org3table: affiliation unique constraints = (partner, competitor, ally)-------------------------------------affiliation_id affiliation100 partner101 competitor102 ally103 competitor1xx etcEach organization is connected to other org(s) as a business partner or competitor. (which I ignore for the moment).I have tried a variety of self joins, and many to many joins, to no avail.I have no idea how to select "business partners" for each organization that do not include the ego partner.all I have so far is this ( less all the many to many joins and self joins attempts etc.)select p.partnum as "partner id", o.org as "self", p.member_id as "business partner",a.affiliationfrom testorg ojoin partners p on o.org = p.member_idjoinorder by p.partnum asc, o.orgthe sql returns a duplicate list for self (ego) and business partner (alter orgs):
partner id self business partner 100 Org1 Org1 100 Org2 Org2 100 Org3 Org3 101 Org1 Org1 101 Org25 Org25 102 Org2 Org2 102 Org3 Org3 103 Org4 Org4 104 Org1 Org1 104 Org16 Org16
I have gotten various Cartesian joins showing every org related to every other, but have not been unable to properly filter the 'partner organizations column to exclude 'ego' e.g. the organization that "others" are related to.Can anybody offer a solution that selects only the partners that are linked to each organization?
thanks very much,glenn B
