SQL join with composite primary key

Question

I have to join two tables. But in one table primary key is not there,composite primary key is there,means three columns put together uniquely define a row of that table. I have those three columns in the other table too.rest nothing is common. Is there any way to join these two tables.please explain with the help of example

You don't need a key to join tables. It will just be less efficient. — Barmar, Dec 22 '14 at 17:28
Your question isn't clear. What problem are you having with joining the tables? — Barmar, Dec 22 '14 at 17:29

score 79 · Answer 1 · answered Dec 22 '14 at 17:28

79

You can use AND in the expression for the ON criteria and demand the fields are all equal there.

SELECT * 
FROM Table1
INNER JOIN Table2
ON Table1.Key1 = Table2.Key1 AND Table1.Key2 = Table2.Key2 AND Table1.Key3 = Table2.Key3

answered Dec 22 '14 at 17:28

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SQL join with composite primary key

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