Unexpected result in a equivalence transfer query

(1.1) By Wang Ke (krking) on 2021-08-30 16:22:02 edited from 1.0

Hello developers,

We found a testcase making SQLite outputs the wrong result as follows:

```
CREATE TABLE t1(a INT PRIMARY KEY);
INSERT INTO t1(a) VALUES(1),(2),(3);
CREATE TABLE t2(x INTEGER PRIMARY KEY,y INT);
INSERT INTO t2(y) VALUES(2),(3);
SELECT * FROM t2,t1 WHERE t2.y=t1.a AND t1.a=t2.x; -- expected: empty
SELECT * FROM t2,t1 WHERE likely(t2.y=t1.a) AND unlikely(t1.a=t2.x); -- unexpected: two lines
```

Presumably, this is a legacy issue related to the [recent fix (check-in f1f9b5de)](https://sqlite.org/src/info/f1f9b5de3c59489b) for the [equivalence transfer problem](https://sqlite.org/forum/info/eb8613976acfe23a), you probably forgot to consider the condition using `PRIMARY KEY` when dealing with equivalent transfer optimization.

Looking forward to your reply, further details will be appreciated!

(2) By Dan Kennedy (dan) on 2021-08-30 17:11:23 in reply to 1.1 [link]

Thanks for this. It was as you suggest - the equivalence transfer problem was still lurking for "INTEGER PRIMARY KEY" indexes. Now fixed here:

[](https://sqlite.org/src/ci/46e28cbc)

Cheers,

Dan.