T-SQL: Rookie Question on Best Approach for Selecting

Posted on 2011-09-20
Medium Priority
Last Modified: 2012-05-12
I'm looking for the best approach on identifying, then deleting, some customer data.  

There's tables for basic customer info, telephone/email info, and marketing info.  Some customers have email info, some don't.  The problem I'm trying to deal with is identifying those customers who don't an email address, yet have asked us to email them marketing info.  

My select statement is:
SELECT entity.entity_id,  phone.phone_no, phone.phone_type, attr_ent.attr_val
FROM   (entity entity INNER JOIN attr_ent attr_ent ON (entity.entity_id=attr_ent.entity_id) AND (entity.co_cd=attr_ent.co_cd))
LEFT OUTER JOIN phone phone ON entity.phone_id=phone.phone_id
WHERE  attr_ent.attr_val LIKE 'e-%'

It gets me data like:
00001003        NULL                           NULL      E-Newsletter        
00001003        NULL                           NULL      E-Training Updates  
00001035        952-123-4567      Direct      E-Newsletter        
00001035        john.doe@acme.com      Email      E-Newsletter        
00001035        952-123-4567      Direct      E-Training Updates  
00001035        john.doe@acme.com      Email      E-Training Updates  
00001240        507-321-9876      Fax      E-Newsletter        
00001240        507-321-9876      Fax      E-Training Updates  

Customer numbers 00001003 and 00001240 should have their requesst for marketing info deleted, as there's no where to send it.  However, customer 00001035, has an email address and should get the marketing info.

I'm getting stuck doing the deletes on customers like 00001035 because I can't figure out how to identify them as valid requests.
Question by:anordquist
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 5
LVL 18

Expert Comment

ID: 36568584
could you do something like

DELETE entity WHERE entity.entity_id IN(
SELECT entity.entity_id
FROM   (entity entity INNER JOIN attr_ent attr_ent ON (entity.entity_id=attr_ent.entity_id) AND (entity.co_cd=attr_ent.co_cd))
LEFT OUTER JOIN phone phone ON entity.phone_id=phone.phone_id
WHERE  attr_ent.attr_val LIKE 'e-%'  AND phone.phone_no IS NULL AND phone.phone_type IS NULL)


Author Comment

ID: 36570057
The marketing info is in the attribute table.  There's one row per customer per marketing info type.  I  can delete the row safely if the phone.phone_type is NULL, but what happens when the check comes up with a phone.phone_type equal to "Phone" rather than to "E-Mail".  The attribute table row gets deleted, even if there might be a later record in the phone table for that customer that has the email info.

These aren't the exact names for the columns
               customer table

Author Comment

ID: 36570098
The prior comment got away from me.....

Customer table

Phone table      (used for phone, fax, website, email, etc.)

Attribute-customer table

Attribute table

So, if a customer doesn't have an email address, yet has requested marketing info, I want to delete the corresponding row in the attribute-customer table.  I need to be able to check all of the rows in the phone table for the customer before I can determine if a deletion is warranted.
Moving data to the cloud? Find out if you’re ready

Before moving to the cloud, it is important to carefully define your db needs, plan for the migration & understand prod. environment. This wp explains how to define what you need from a cloud provider, plan for the migration & what putting a cloud solution into practice entails.

LVL 21

Expert Comment

by:Alpesh Patel
ID: 36573150
Use Merge statement of SQL Server 2008 R2.

Merge Souce

When Match
When not MAtche

Author Comment

ID: 36573700
I'm running SQL Server 2005.

Accepted Solution

anordquist earned 0 total points
ID: 36905683
Delete question, no solutions are forthcoming.

Author Closing Comment

ID: 36935287
Delete the question, no answers for SQL Server 2005.

Featured Post


Modern healthcare requires a modern cloud. View this brief video to understand how the Concerto Cloud for Healthcare can help your organization.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

The Delta outage: 650 cancelled flights, more than 1200 delayed flights, thousands of frustrated customers, tens of millions of dollars in damages – plus untold reputational damage to one of the world’s most trusted airlines. All due to a catastroph…
What if you have to shut down the entire Citrix infrastructure for hardware maintenance, software upgrades or "the unknown"? I developed this plan for "the unknown" and hope that it helps you as well. This article explains how to properly shut down …
Using examples as well as descriptions, and references to Books Online, show the documentation available for date manipulation functions and by using a select few of these functions, show how date based data can be manipulated with these functions.
Via a live example, show how to set up a backup for SQL Server using a Maintenance Plan and how to schedule the job into SQL Server Agent.
Suggested Courses

777 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question