Sql query with multiple joins to same table

Question

I have to write a query for a client to display business officers' names and title along with the business name
The table looks like this
AcctNumber
OfficerTitle
OfficerName
RecKey
90% of the businesses have exactly 4 officer records, although some have less and some have more.
There is a separate table that has the AcctNumber, BusinessName about 30 other fields that I don’t need
An individual account can have 30 or 40 records on the other table.
The client wants to display 1 record per account.
Initially I wrote a query to join the table to itself:
Select A.OfficerTtitle, A.OfficerName, B.OfficerTitle, B.OfficerName, C.OfficerTtitle, C.OfficerName, D.OfficerTitle, D.OfficerName where A.AcctNumber = B.AcctNumber and A.AcctNumber = C.AcctNumber and A.AcctNumber = D.AcctNumber
This returned tons of duplicate rows for each account ( number of records * number of records, I think)
So added
And A.RecKey > B.RecKey and B.RecKey > C. RecKey and C.RecKey . D.RecKey
This works when there are exactly 4 records per account. If there are less than 4 records on the account it skips the account and if there are more than 4 records, it returns multiple rows.
But when I try to l join this to the other table to get the business name, I get a row for every record on the other table
I tried select distinct on the other table and the query runs for ever and never returns anything
I tried outer joins and subqueries, but no luck so far. I was thinking maybe a subquery - if exists - because I don't know how many records there are on an account, but don't know how to structure that
Any suggestions would be appreciated

Answer 1

Welcome to the forum!
user13319842 wrote:
I have to write a query for a client to display business officers' names and title along with the business name
The table looks like this
AcctNumber
OfficerTitle
OfficerName
RecKey
90% of the businesses have exactly 4 officer records, although some have less and some have more.
There is a separate table that has the AcctNumber, BusinessName about 30 other fields that I don’t need
An individual account can have 30 or 40 records on the other table.
The client wants to display 1 record per account.As someone has already mentioned, you should post CREATE TABLE and INSERT statements for both tables (relevant columns only). You don't have to post a lot of sample data. For example, you need to pick 1 out of 30 or 40 rows (max) for the same account, but it's almost certainly enough if you post only 3 or 4 rows (max) for an account.
Also, post the results you want from the sample data that you post, and explain how you get those resutls from that data.
Always say which version of Oracle you're using. This sounds like a PIVOT problem, and a new SELECT .... PIVOT feature was introduced in Oracle 11.1. If you're using Oracle 11, you don't want to have to learn the old way to do pivots. On the other hand, if you have Oracle 10, a solution that uses a new feature that you don't have won't help you.
Whenever you have a question, please post CREATE TABLE and INSERT statements for some sample data, the results you want from that data, an explanation, and your Oracle version.
Initially I wrote a query to join the table to itself:
Select A.OfficerTtitle, A.OfficerName, B.OfficerTitle, B.OfficerName, C.OfficerTtitle, C.OfficerName, D.OfficerTitle, D.OfficerName where A.AcctNumber = B.AcctNumber and A.AcctNumber = C.AcctNumber and A.AcctNumber = D.AcctNumber Be careful, and post the exact code that you're running. The statement above can't be what you ran, because it doesn't have a FROM clause.
This returned tons of duplicate rows for each account ( number of records * number of records, I think)
So added
And A.RecKey > B.RecKey and B.RecKey > C. RecKey and C.RecKey . D.RecKey
This works when there are exactly 4 records per account. If there are less than 4 records on the account it skips the account and if there are more than 4 records, it returns multiple rows.
But when I try to l join this to the other table to get the business name, I get a row for every record on the other table
I tried select distinct on the other table and the query runs for ever and never returns anything
I tried outer joins and subqueries, but no luck so far. I was thinking maybe a subquery - if exists - because I don't know how many records there are on an account, but don't know how to structure that
Any suggestions would be appreciatedDisplaying 1 column from n rows as n columns on 1 row is called Pivoting . See the following link fro several ways to do pivots:
SQL and PL/SQL FAQ
Pivoting requires that you know exactly how many columns will be in the result set. If that number depends on the data in the table, then you might prefer to use String Aggregation , where the output consists of a huge string column, that contains the concatenation of the data from n rows. This big string can be formatted so that it looks like multiple columns. For different string aggregation techniques, see:
http://www.oracle-base.com/articles/10g/StringAggregationTechniques.php
The following thread discusses some options for pivoting a variable number of columns:
Re: Report count and sum from many rows into many columns