SQLite中的DISTINCT子句

sqlite> SELECT * FROM t GROUP BY b;
2|5
4|6
(for each b: one (unpredictable) value of a)

sqlite> SELECT * FROM (SELECT * FROM t ORDER BY a DESC) GROUP BY b;
1|5
3|6
(for each b: the row with min a)

sqlite> SELECT * FROM (SELECT * FROM t ORDER BY a ASC) GROUP BY b;
2|5
4|6
(for each b: the row with max a)

使用:

  SELECT MIN(t.a) AS A,
         t.b
    FROM TABLE t
GROUP BY t.b