Question on Join properties

[AlexanderBB]

Looking at join properties there's 3 options

1. Only include rows where the joined fields from both tables are equal.
2. Include ALL records from 'Table1' and only those records from
'Table2' where the joined fields are equal.
3. Include ALL records from 'Table2' and only those records from
'Table1' where the joined fields are equal.

But what if you want to only include rows from 'Table1' where the joined fields from both tables are equal ?

All of the 3 options give two of each, one from each table.

Thanks, ABB

 

[SydneyGeek]

The reason that they mention both sides of the join is, that is how databases think about joins.
Type 1 above is an EQUI-JOIN: the default when you join 2 tables. You only see rows where the join (key) fields match in both tables.
Types 2 and 3 are OUTER JOINS: They let you detect mismatched data, e.g. Customers with no Orders. You will also see them described as LEFT and RIGHT joins (2 is LEFT, 3 is RIGHT), indicating the direction of the mismatch.

If you only want to see data from Table1 where both tables are equal, leave the join as Type 1, and only include fields from Table1 on the grid.

Denis

 

[AlexanderBB]

Thanks Denis, that's often bugged me. I've have to print out your reply and stick it on the wall!

Regards, ABB