MySQL - 选择与其他字段不同的字段

Question

我有一张 table ..

field_1 | field_2 | field_3 | field_4data_1  | data_2  | data_3  | data_4

all the data withing tablename can potentially repeat.

I want to select unique field_1's so that i dont get any repeats, but I also need the rest of that row of data.

SELECT DISTINCT field_1, field_2, field_3, field_4 FROM tablename;

上面的查询显然是行不通的。所以我的问题是我该怎么做？

更新

如何防止显示重复项。

如果我有

data_1|data_2|data_3|data_4data_1|data_2|data_3|data_4data_6|data_7|data_8|data_9

只会显示结果

data_6|data_7|data_8|data_9

Answer 1

你能给更多的记录吗？下面的查询将为每个组生成唯一的 field_1 但随机记录(尤其是在处理大型数据库时)。

SELECT field_1, field_2, field_3, field_4
FROM   TableName
GROUP  BY field_1

• SQLFiddle Demo

更新 1

SELECT  field_1, field_2, field_3, field_4
FROM    TableName
GROUP   BY field_1, field_2, field_3, field_4
HAVING  COUNT(*) = 1