Recent content by hangglide

Yes, I am looking for the complete list of all segments in an upstream path (all the possible tree branches). What I really need to do is test if one record is upstream of another record. Both will be randomly selected by another part of the script. If one is upstream of the other record...

Wayne, I am still trying and this one still has me stumped. Thanks for the note about recordsets. I will try to do some more reading on those to see if I can get a solution. Thanks for your help. Leo

Actually, that is close but not right. The grid_code is a hint as to how this data was created. Imagine a (huge) grid with each cell numbered consecutivly starting with 1 in the top left corner. E.G. 1, 2, 3, 4, 5 6, 7, 8, 9, 10 11, 12, 13, 14, 15 16, 17, 18, 19, 20 21, 22, 23, 24...

I should have left out GRID_CODE. It is not important for this project. ARCID is important. Streams flow from the "FromNode" to the "ToNode" downstream. Each record represents a stream segment. Sometimes more than one stream segment has the same "ToNode" because sometime streams flow...

You are right. I don't need to keep track of the "from" and "to" nodes in my final temp table. The only reason I did it here was so that I could be sure it was working right. I really only need the ID field (ARCID). I can get the rest of the data from a join later. I just updated a previous...

Yep, This is a tough one for me as I am not that good at VB. I looked closely at your code and I understand the concept. I "pulled apart" you code and tried to recreate it myself just for learning reasons (and because for the life of me I can't call your function properly). ha Here is what I...

Okay, Wayne. I am stumped. I have spent hours trying to implement your code. I am not exactly sure which "keys" go where. I like the idea and I can live with the join after a temp table is created (if I could get that far). I am reworking the script (to try to understand it better). So far...

Thanks Wayne, You answer sounds like it might work. I will give it a try. Leo

Nested/recursive/BOD problem Does anyone know how to create the "lft" annd "rgt" fields in the BOM Joe Celko example? I have over 100,000 records in my table. Example database attached. http://www.mvps.org/access/queries/qry0023.htm

I have a much simpler "recursive" question. I have a stream network that does not have other waterbodies. How would I go about constructing a recursive query that simply selected all upstream records from any given record? My data have a the same tnode and fnode fields. Thanks, Leo

Is it possible to write a query on a network table (not a computer network). For example: Streams flow into larger streams. Each stream has a nodeID at the top and bottom. So one stream from its headwater migh flow (simplisticly) from node 1 to 2, then from 2 to 3 and from 3 to 4. A second...

Thanks Thank you for your helpful replies. FoFa's query worked great. I took a database class in college and we learned Oracle there so that is what I was familliar with. The inner and outer joins were new to me. Thanks for your help. FYI, I am now using the Access RDBMS. The crosstab...

Didn't Work Thanks for the suggestion Paul but that didn't work like I had hoped. The example I provided was just an example of an INTERSECT query. I guess I will have to get specific with my actual problem. :-) Here it is. This is the INTERSECT query I want to run. SELECT Comment...

Sorry if this has already been answered. I searched and couldn't find it. How do I do an INTERSECT query in Access? It is my understanding that Access does not support the INTERSECT query. Is this right? The syntax for an INTERSECT query is: select field1, field2, … field_n from...

Rnd function? Are you looking for a function that will select a random record? You could do it in VBA like this: RandomRecordID = (UpperBound - LowerBound + 1) * Rnd (Timer) + LowerBound Where RandomPointID is the ID for the randomly selected point; UpperBound is a count of records...