How can I find the table row number in an original table from an inner join

Question

0.00/5 (No votes)

See more:

I am trying to do a search based on an inner join. I combine Birth, death and cemetery records. However, I am looking to update specific rows that may be in one of the tables.
The problem is that when I use an inner join it will only show those people that perfectly match between all three tables. So, if I have 100 people and only 80 of those have death and cemetery records then only those rows populate the data table. This means that 20 rows out of the 100 are not there. Any suggestions on how to proceed with finding the actual row number associated with the data from the inner join statement vs the tables it comes from

for instance,

Birth may be row 1 in the birth table
Death may be row 60 in the death table
and cemetery may be 70 in the cemetery table

I need to know these positions for my data update statement.

What I have tried:

I Have tried to find the row index, but it relates the current table being populated. Which gives the wrong row index in some cases.

Posted 20-Jan-19 14:45pm

Member 11856456

Updated 20-Jan-19 17:53pm

Add a Solution

2 solutions

Solution 2

If you're trying to keep data in different tables "sync'd up" with each other solely by row number in the tables, you're doing it very, very wrong.

This is why tables should have primary keys and referencing keys in other tables, called foreign keys.

Posted 20-Jan-19 17:54pm

Dave Kreskowiak

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

MadMyche · Accepted Answer · 2019-01-20T15:13:00

Change it up to use an OUTER JOIN instead

SQL

SELECT    b.BirthIndex,    b.{other data}
     ,    d.DeathIndex,    d.{other data}
     ,    c.CemeteryIndex, c.{other data}
FROM      BirthRecords           b
LEFT OUTER JOIN DeathRecords     d ON b.PersonID = d.PersonID
LEFT OUTER JOIN CemeteryRecords  c ON b.PersonID = c.PersonID

This will bring up everyone that you have a record for in the Birth table, and will bring up any records that are present in the related tables for Death and/or Cemetery.

What you will need to account for in your code is that you are going to get NULLs for the DeathIndex and/or CemetaryIndex if there is no corresponding record.

One thing to consider would be to add another table for the people in general (PersonsTable) that has their main information, and use that as the "main" table and Left Join the others. It is entirely possible to end up with death and or cemetery records and not have a birth record locally.