query Linking Two Tables with Null Values

[johnnyc]

i have 2 tables that i am linking on a field that matches with null values on both tables but it either pulls nothing or when i put a right join pulls just one tables data.

i have also confirmed both are pulling from the same data source, so no issues with field properties and confirmed they are null values in each field within both tables.

Is there a trick to this?

Thanks!

 

[spikepl]

Not sure exactly what your issue is, but if you expect a "match" on fields containing nulls then don't!

Null=Null evaluates to False in queries

 

[johnnyc]

ok, well i need to be able to identify any nulls in both tables and link some information. Any quick work arounds?

 

[JHB]

Show your SQL string.

 

[RainLover]

Johnnyc

What is your primary key. This is what you should be joining on.

 

[johnnyc]

thansk RainLover. I actually made the null values 0 and matched off of that but your right about the primary key.

Thanks !

 

[RainLover]

I may be right, I maybe wrong but:

Null cannot Equal Null.

Null is unknown

The = sign means becomes.

A = 3 + 7 Equals 10 Looks like Equals and in this case gives the same result but it really is not Equals as we would normally use it..

Therefore as long as the sun keeps rising you cannot join two Nulls of equal value because there is none.