SQLite Forum

LEFT JOIN Misunderstanding
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Keith said:
```
An equijoin is a projection (join) of two tables where some item in one table is equal to some item in another table.

SELECT * FROM A, B WHERE A.X == B.X;

is an equijoin of tables A and B.
```
If the A->B relationship is one-to-many, are multiple rows returned? That is, if A.X matches multiple B.X's, is a row returned for each match? And what about many-to-many? And many-to-one? Without DISTINCT, what happens?