Getting Duplicate results when using INNER JOIN - sql

Question

I have 3 tables. One with user names, one with a bunch of data, and then one that links the 2 tables together via their ID's. When I try and join the 3 with an INNER JOIN, I get a bunch of duplicate rows. For example, if the data table only has 2000 rows, once I try and use the inner join to connect the 3 tables, I get an output that shows 100,000 rows. Does this have something to do with the fact that my Data table has more rows than my User name table and the inner join doesn't play nicely? Is it possible to inner join one table that has more rows than the other?
EDIT FOR CLEARITY
For this database I import data that looks something like this:
-Names-----------Numbers-----------Item---------------Cost---
John Smith 111-1111 Pencils 100.75
Joe Stevens 222-2222 Paper 35.34
Mike Jones 333-3333 Staples 23.86
John Smith 111-1111 Boxes 11.76
As you can see John Smith is listed twice, for two separate items. I would like to optimize this, but separating the original data and putting things in their own table with only one iteration.
ID---Name--- ID----Numbers ID---Items------Cost
1 John Smith 1 111-1111 1 Pencil 100.75
2 Joe Stevens 2 222-2222 2 Paper 35.34
3 Mike Jones 3 333-3333 3 Staples 23.86
4 Boxes 11.76
Now that things are optimized, I need to be able to still run a query that could match John Smith with both the pencils and the boxes. This is why I created the link table that holds the IDs in the correct sequence they need to be in.
Name.ID Number.ID Item.ID
1 1 1
2 2 2
3 3 3
1 1 4
Now if I wanted to run a report that recreates the original data dump, I would run a query that just joins the 3 tables with an inner join. The issue though, is that I'm getting results with tons of duplicates, rather than just simply outputting that data as it should be. I get something like this:
-Names-----------Numbers-----------Item---------------Cost---
John Smith 111-1111 Pencils 100.75
John Smith 111-1111 Pencils 100.75
John Smith 111-1111 Pencils 100.75
John Smith 111-1111 Pencils 100.75
John Smith 111-1111 Pencils 100.75
Joe Stevens 222-2222 Paper 35.34
Joe Stevens 222-2222 Paper 35.34
Joe Stevens 222-2222 Paper 35.34
Joe Stevens 222-2222 Paper 35.34
Mike Jones 333-3333 Staples 23.86
Mike Jones 333-3333 Staples 23.86
Mike Jones 333-3333 Staples 23.86
Mike Jones 333-3333 Staples 23.86
John Smith 111-1111 Boxes 11.76
John Smith 111-1111 Boxes 11.76
John Smith 111-1111 Boxes 11.76
John Smith 111-1111 Boxes 11.76
The desired output would simply be:
-Names-----------Numbers-----------Item---------------Cost---
John Smith 111-1111 Pencils 100.75
Joe Stevens 222-2222 Paper 35.34
Mike Jones 333-3333 Staples 23.86
John Smith 111-1111 Boxes 11.76

Answer 1

try this one
Select Distinct t1.Names,t2.Number,t3.Item,t3.Cost
From
tableName t1
inner join tableNum t2
on t1.ID = t2.ID
inner join tableItem t3
on t1.ID = t3.ID