CODEWITHSUNDEEP
sqljoin
Shawn H
Shawn H

Reputation: 1118

SQL Join Problem... what is it called?

I have two tables that are joined. I've included the 'output' of the joined tables. I'm wondering what is this join problem called? There are duplicating rows.

Table 1          Table 2
ID     Name     ID Name
 1     Joey         4 Mary
2     Shawn      5 Xavier
3     Mark         6 Gary

The join output is:

ID     Name     ID Name
4     Mary     1 Joey
4     Mary     2 Shawn
4     Mary     3 Mark
5     Xavier   1 Joey
5     Xavier   2 Shawn
5     Xavier   3 Mark
6     Gary     1 Joey
6     Gary     2 Shawn
6     Gary     3 Mark

Upvotes: 3

Views: 182

Answers (4)

Pierre-Alain Vigeant
Pierre-Alain Vigeant

Reputation: 23093

Based on your output, your query is something like

SELECT * FROM Table2, Table1

This is called a CROSS JOIN and this is the normal behavior that for each row in table2, the values from table1 will be appended.

What you seem to want is a UNION

SELECT * FROM Table1
UNION
SELECT * FROM Table2

Upvotes: 0

shahkalpesh
shahkalpesh

Reputation: 33474

It is CROSS JOIN.

Upvotes: 1

Chris McCall
Chris McCall

Reputation: 10397

If memory serves, that's called a Cartesian Product.

Upvotes: 8

Donut
Donut

Reputation: 112825

I think your problem is that you want to use UNION, not JOIN.

Example:

SELECT * FROM Table1 UNION SELECT * FROM Table2;

Should give you:

ID  Name
1   Joey
2   Shawn
3   Mark
4   Mary
5   Xavier
6   Gary

Is this what you're trying to do?

Upvotes: 3

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