Best way to make Query to Select Child Without Parrent

[angjbsca]

Hi here Again... I have a 2 tables Parent,child... I need to take out all the records with Child without Parent and viceversa,,,right now I'm doing with left join but take much time because those tables are huge.my question is ..exist another other way to acomplish that?

 

[SQLDenis]

Try NOT EXISTS

Denis The SQL Menace
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http://sqlservercode.blogspot.com/

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[jbenson001]

You should consider having a relationship on the tables so that this kind of problem does not occur.

 

[angjbsca]

here my join, how I can change to Not exists logic?.

select a.bd,a.bt,a.bq,a.sm
from mm a
left join md b
on a.bd = b.bd and
a.bt = b.bt and
a.bq = b.bq and
a.sm = b.sm
where b.bd is null
and b.bt is null
and b.bq is null
and b.sm is null

 

[SQLDenis]

untested

select a.bd,a.bt,a.bq,a.sm
from mm a
where not exists (select * from md b where a.bd = b.bd and
    a.bt = b.bt and
    a.bq = b.bq and
    a.sm = b.sm)

Denis The SQL Menace
SQL blog:

http://sqlservercode.blogspot.com/

Personal Blog:

http://otherthingsnow.blogspot.com/