Duplicate data

[w0od0o]

hi, i have created 3 queries and now i want to create a 4th to filter all the data to certain dates ect.. but when i add all 3 queries into 1 using all fields in the queries i get duplicate data,

i think it has something to do with the foreign keys but unsure on how to remove the problem,

thanks

w0od0o

 

[Rabbie]

You are going to have to give us some moe information. Details of your queries and your table structure as a minimum. Some real data would also be helpful.

 

[w0od0o]

here is a copy of my db, hope this helps

 

[w0od0o]

i have started my db again and changed quite a few things (for the better i hope ) but i was kinda hoping my problem with the duplicate data would have been an isolated issue but it appears i must be making the same mistakes as before,

i would be very grateful if someone could take a look at my new db and explain why im getting duplicate or false data

many thanks

w0od0o

 

[Rabbie]

Its very simple. Unless all the data sources are linked the query will generate a so-called cartesian join. This means that if you have 10 records in Table1 and 8 records in Table2 that unless they ae linked you get 80 records in the output.

 

[w0od0o]

so its more of a relationship issue than a query issue?

 

[Rabbie]

so its more of a relationship issue than a query issue?

Exactly. You need to make sure you have the correct joins in your query.