How can i concatenate two fact tables? Item 'field name' already exists in the collection.

[vitexo87]

I have several facts and need to make them into one, how can I do?

[Anonymous]

Hi @vitexo87,

   you have two options. If the tables have an equal column you can use the "Merge Queries", in other case you can use the "Append Queries". Which is your case?

[vitexo87]

in my case I have several tables facts that several fields are the same, I did a test with the option to add query, this is my best option?

[Anonymous]

I don't know which is the best option, but

if you look at this screenshot you'll see the different results from the "Merge queries" and "Append queries". All the tables had Column1 = {1,2,3,4,5,6}. As you can see with the merge the result is much more clear, but it depends on what you have to do and your dataset configuration.

#I'M Not An Expert#

[pqian]

Merge is a join operation, which changes the shape of the table (more columns)

Append is an union operation, which doesn't change the shape conceptually but adds more rows (if used as intended. If you append mismatched schema together it unions them)

[pqian]

Try "Edit Queries" -> "Append Queries"

[vitexo87]

and then ?, sorry it was not clear to me

[pqian · Accepted solution]

First you should select all fact tables you want to append.

Then you can goto the first one, select append queries, and then append all the other tables to this query. 

Next you can goto the other queries, right click on them and mark them as not loaded (Enable Load = false). This will save some space on the model.

Finally, load the first table, you should have a table with all fact tables combined. This is effectively a UNION operation.