Best way to run query AFTER checking criteria

[tagteam]

I would like to run an append query but only after I have checked a table for existing data. I want to see if a ralicarID exists in a table and if it doesnt the query should run. if the railcarid does exist but also has a check in and check out date then the query can also run.



I am not very good at programming but I was thinking something like this

Dim RailcarInDatabase as number
' run query here that checks for the railcar id and returns a value
if railcarID in table then RailcarInDatabase =1 else RailcarInDatabase =0
And if If RailcarID in table and DateInShop is not null and DateOutShop is not null then RailcarInShop = 0

Something like that which will allow me to run the query only if the car is not in the database or it is currently not in the shop.

Any help is appreciated.

[orange]

Sounds reasonable from 30000 feet. But we need more info re your "business rules/facts" and a picture of your tables and relationships.

[tagteam]

Well I have been thinking about it and I think it will be easier to just create a new checkbox called InShop. Then when the button is clicked it will start the query and select the InShop checkbox. if the box is already selected it will stop the query and give the user a message that it is in the shop. Then I dont have to worry about checking the dates.

That will make it a simple if statement. If InShop = True then quit else run query.