dlookup

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In access table "class 1", query design, for a field expression:
lookup in Table "class spelling" the field [ggwareaname] and match the value
that corresponds to "class 1" field [ggwareaname1] and return the value in
table "class spelling" field [ggwareanum]
 
A Lookup is, in SQL, a JOIN (mainly if the lookup is uniquely defined).


So, bring the required table(s), join them, and get the required field(s)
from the relevant table.


***If*** you need to 'lookup' in the same table (such as a parent-child
like table), bring the table TWICE.



Hoping it may help,
Vanderghast, Access MVP
 
For reason I don't think I can explain I would prefer, if I can, to perform
the expression in my append query without using brining other tables in. O
ris it all the same thing?

Michel Walsh said:
A Lookup is, in SQL, a JOIN (mainly if the lookup is uniquely defined).


So, bring the required table(s), join them, and get the required field(s)
from the relevant table.


***If*** you need to 'lookup' in the same table (such as a parent-child
like table), bring the table TWICE.



Hoping it may help,
Vanderghast, Access MVP


sierralightfoot said:
In access table "class 1", query design, for a field expression:
lookup in Table "class spelling" the field [ggwareaname] and match the
value
that corresponds to "class 1" field [ggwareaname1] and return the value in
table "class spelling" field [ggwareanum]
Click to expand...
Click to expand...
 
If you use a lookup, you effectively 'bring' another table in the scenario.
It seems to be the same thing, but a join would probably be faster than
re-initializing explicitly a lookup (DLookup) for each row.

Vanderghast, Access MVP


sierralightfoot said:
For reason I don't think I can explain I would prefer, if I can, to
perform
the expression in my append query without using brining other tables in. O
ris it all the same thing?

Michel Walsh said:
A Lookup is, in SQL, a JOIN (mainly if the lookup is uniquely defined).


So, bring the required table(s), join them, and get the required field(s)
from the relevant table.


***If*** you need to 'lookup' in the same table (such as a parent-child
like table), bring the table TWICE.



Hoping it may help,
Vanderghast, Access MVP


sierralightfoot said:
In access table "class 1", query design, for a field expression:
lookup in Table "class spelling" the field [ggwareaname] and match the
value
that corresponds to "class 1" field [ggwareaname1] and return the value
in
table "class spelling" field [ggwareanum]
Click to expand...
Click to expand...
Click to expand...
 
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