Solved

MS SQL Syntax

Posted on 2013-12-03
6
181 Views
Last Modified: 2013-12-04
I am trying to delete orphan records where the parent has been deleted (there is no FK defined).

This works:

select * from tblBVMeterReadingErrors a where not exists (Select 0 from tblBVMeterReadings b
where a.BV_Meter_Reading_ID = b.BV_Meter_Reading_ID);

But this doesn't:

delete from tblBVMeterReadingErrors a where not exists (Select 0 from tblBVMeterReadings b
where a.BV_Meter_Reading_ID = b.BV_Meter_Reading_ID);

What is wrong please?
0
Comment
Question by:slimguy
[X]
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
6 Comments
 
LVL 15

Expert Comment

by:gplana
ID: 39693901
Try this way:

delete from tblBVMeterReadingErrors where BV_Meter_Reading_ID NOT IN (Select BV_Meter_Reading_ID from tblBVMeterReadings
where b.BV_Meter_Reading_ID IS NOT NULL);

Open in new window

0
 
LVL 15

Accepted Solution

by:
gplana earned 100 total points
ID: 39693905
Sorry, I made a mistake: please remove the b.  from my previous solution:

delete from tblBVMeterReadingErrors where BV_Meter_Reading_ID NOT IN (Select BV_Meter_Reading_ID from tblBVMeterReadings
where BV_Meter_Reading_ID IS NOT NULL);

Open in new window

0
 
LVL 6

Expert Comment

by:ButlerTechnology
ID: 39693906
Select * from tblBVMeterReadingErros 
where bv_meterReading_ID not in (Select bv_MeterReadingID from tblBVMeterReading)

Delete from tblBVMeterReadingErros 
where bv_meterReading_ID not in (Select bv_MeterReadingID from tblBVMeterReading)

Open in new window


The above code should work.
Tom
0
Salesforce Made Easy to Use

On-screen guidance at the moment of need enables you & your employees to focus on the core, you can now boost your adoption rates swiftly and simply with one easy tool.

 
LVL 15

Expert Comment

by:gplana
ID: 39693927
ButlerTechnology, this is exactly my solution. I just only  add a filter to avoid NULL values which some times could cause problems in comparisions inside the NOT IN.
0
 
LVL 9

Expert Comment

by:QuinnDex
ID: 39693943
this should do it for you check you are getting the correct results with the select before using the delete

select * from tblBVMeterReadingErrors where not in(Select 0 from tblBVMeterReadings
where tblBVMeterReadingErrors .BV_Meter_Reading_ID = tblBVMeterReadings.BV_Meter_Reading_ID);

Open in new window




delete from tblBVMeterReadingErrors where not in(Select 0 from tblBVMeterReadings
where tblBVMeterReadingErrors .BV_Meter_Reading_ID = tblBVMeterReadings.BV_Meter_Reading_ID);

Open in new window

0
 

Author Closing Comment

by:slimguy
ID: 39694870
Many thanks, I should have seen that myself - got a mental block last night!
0

Featured Post

Enroll in May's Course of the Month

May’s Course of the Month is now available! Experts Exchange’s Premium Members and Team Accounts have access to a complimentary course each month as part of their membership—an extra way to increase training and boost professional development.

Question has a verified solution.

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

Suggested Solutions

Title # Comments Views Activity
SQL Syntax to get a value associated with most recent date 16 64
SQL 2012 Report Builder 3.0 query 2 24
mssql 7 32
t-sql left join 2 34
Slowly Changing Dimension Transformation component in data task flow is very useful for us to manage and control how data changes in SSIS.
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…
Via a live example, show how to extract information from SQL Server on Database, Connection and Server properties
Using examples as well as descriptions, and references to Books Online, show the documentation available for datatypes, explain the available data types and show how data can be passed into and out of variables.

751 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