JW,
I'm trying to understand LEFT JOIN as we go - but it's not working. This query SELECT * FROM CUSTOMERS LEFT JOIN CALLS ON CUSTOMERS.PHONE = CALLS.PHONE WHERE CUSTOMERS.DATE = "02/28/12" AND (CALLS.PHONE IS NULL OR CALLS.DATE = "02/28/12") Is giving me some results which I'm not quite sure what they are - but it's not the right results. The way I'm testing is, on 02/28/12 I had 57 Customers created in the CUSTOMERS table. I also had a total of 105 Calls recorded in the CALLS table. Some calls were from the same customers more then once. Essentially, I need the result to be 86 which I got from some manual calculations. Out of those 86 records, 1 record is in the CUSTOMERS table but not in the CALLS table. The other 85 were in both tables. The above LEFT JOIN query gave me 69 records and quite a few duplicate entries. I'm trying to dissect it to understand what exactly it selected. Thanks! ~~ LUCi5R e: luc...@luci5r.com w: http://www.luci5r.com From: Johnny Withers [mailto:joh...@pixelated.net] Sent: Wednesday, February 29, 2012 1:30 PM To: luc...@luci5r.com Cc: mysql@lists.mysql.com Subject: Re: Getting data from 2 tables if records have same date! Sounds like you need to LEFT JOIN: SELECT * FROM CUSTOMERS LEFT JOIN CALLS ON CUSTOMERS.PHONE = CALLS.PHONE AND CALLS.DATE = "02/28/12" WHERE CUSTOMERS.DATE = "02/28/12" But that would only get customers created on 2/28 AND having a call on 2/28 OR not call at all on 2/28. This would give you customers created on 2/28 with no calls AND customers created on 2/28 with a call on 2/28: SELECT * FROM CUSTOMERS LEFT JOIN CALLS ON CUSTOMERS.PHONE = CALLS.PHONE WHERE CUSTOMERS.DATE = "02/28/12" AND (CALLS.PHONE IS NULL OR CALLS.DATE = "02/28/12") JW On Wed, Feb 29, 2012 at 1:02 PM, LUCi5R <luc...@luci5r.com> wrote: Guys, I've been working with MySQL for a while (been on & off this list over the last 10 years or so); I'm definitely not a n00b and have worked with SQL extensively. Used JOIN and all quite a bit ... but I haven't done subqueries, union or nested joins. I'm completely stumped on this problem; and Google hasn't been helpful at all. I'll try to be as descriptive as possible. I have 2 tables ... CUSTOMERS and CALLS. Think of Customers table as your Directory. It has the customer's contact information & some other information. In total about 20 fields in there. The Calls table has only about 7 fields. Each time a customer calls in, the conversation details gets recorded in this Calls table. The PHONE field is the key field that joins the CUSTOMERS & CALLS tables. That is the only identifying key that gets written on the Calls record when that customer calls. One thing to note -- It is possible for a customer to exist in the CUSTOMERS table, but not exist in the CALLS table; however, it is not possible for a PHONE # to be in the CALLS table but not in CUSTOMERS table. Essentially, a customer's record has to be created first in the CUSTOMERS table before a call can be recorded from him in the CALLS table. Also, CALLS table can have multiple entries with same PHONE # (Customer called many times - maybe even same day), but CUSTOMERS will only have a single entry for a PHONE #. Here comes my problem ... I have a PHONE SEARCH box with the ability to define a date range; for simplicity sake - we'll use just One Date instead of "DATE ... BETWEEN" for now. When someone searches for a PHONE number, I want to show ALL the CUSTOMERS that: a. Were CREATED on that day (Date defined in Search Criteria) b. Had CALLED in that day (Date defined in Search Criteria) The DATA that I need to pull up and show is in the CUSTOMERS table; not the CALLS table -- so the DATA I need needs to come out of the CUSTOMERS table matching on phone from both tables for the given DATE. In other words - any CUSTOMER that has the PHONE NUMBER which appears in BOTH CUSTOMERS & CALLS table with the DATE defined should pull up. For the life of me - I can't get this to work!! Let's take the date "02/28/12" for example sake. My biggest issue is ... using JOIN, I can pull up ... a. ALL the phone/customers that appeared in the CALLS table with date "02/28/12" b. ALL the phone/customers that appeared in CALLS & CUSTOMERS with date "02/28/12" BUT -- If there's a customer with date "02/28/12" who DOES NOT appear in CALLS table at all - does NOT show up!! And that is because I'm using CUSTOMERS.PHONE=CALLS.PHONE in the JOIN ON clause. So it obviously won't pick up a record where the phone didn't exist in both tables. My initial query was: SELECT * FROM CUSTOMERS JOIN CALLS ON CUSTOMERS.PHONE = CALLS.PHONE WHERE CUSTOMERS.DATE = "02/28/12" AND CALLS.DATE = "02/28/12" I've tried 100's of combinations of this query; many different OR, AND, GROUP BY combinations --- but I can't pull up ALL records from CUSTOMERS with DATE "02/28/12" and ALL records from CALLS with DATE "02/28/12" in a single query. I've hit a wall here. Any ideas/suggestions/advice? THANKS ~~ LUCi5R e: luc...@luci5r.com w: http://www.luci5r.com -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql -- ----------------------------- Johnny Withers 601.209.4985 joh...@pixelated.net
