在这个例子中,我使用SQLite,其中表源已经有一个内置的rowid。根据您使用的数据库,您可能需要添加您自己的自动递增整数列(即整数主键),但这个想法是相同的。
CREATE TABLE Source (num, value);
INSERT INTO Source (num, value) VALUES (1, 3.51);
INSERT INTO Source (num, value) VALUES (2, 'hello');
INSERT INTO Source (num, value) VALUES (1, 3.487);
INSERT INTO Source (num, value) VALUES (2, 'goodbye');
INSERT INTO Source (num, value) VALUES (1, 32.4);
INSERT INTO Source (num, value) VALUES (2, 'foo');
"1","3.51"
"2","hello"
"1","3.487"
"2","goodbye"
"1","32.4"
"2","foo"
SELECT a.num, a.value, b.value
FROM Source a
INNER JOIN Source b ON a.rowid = b.rowid - 1
WHERE a.num = 1 AND b.num = 2
"1","3.51","hello"
"1","3.487","goodbye"
"1","32.4","foo"
数据库?以及如何知道什么值配对?! – 2011-05-23 07:05:35
@marc_s:我的格式!我的美丽格式... – 2011-05-23 07:06:07
是否有一些额外的序列字段(日期或ID),将确切地定义这些行的顺序'Num = 1'和'Num = 2'?例如。我怎么知道“3.51”和“hello”属于? – 2011-05-23 07:06:16