为什么这条SQL语句提示除非同时指定了select top，否则。。。。

[lasker]

SELECT TOP 6 *
FROM (SELECT DISTINCT quote.code, market.name, quote.datetime
FROM market INNER JOIN
quote ON market.id = quote.code
WHERE (quote.code = 72) OR
(quote.code = 215) OR
(quote.code = 216) OR
(quote.code = 217) OR
(quote.code = 218) OR
(quote.code = 219) OR
(quote.code = 220)
ORDER BY quote.datetime DESC) t1

[gezichong]

SELECT TOP 6 quote.datatime as datatime
FROM (SELECT DISTINCT quote.code, market.name, quote.datetime
FROM market INNER JOIN
quote ON market.id = quote.code
WHERE (quote.code = 72) OR
(quote.code = 215) OR
(quote.code = 216) OR
(quote.code = 217) OR
(quote.code = 218) OR
(quote.code = 219) OR
(quote.code = 220)
ORDER BY quote.datetime DESC) t1

[cansum396]

SELECT TOP 6 *
FROM (SELECT DISTINCT quote.code, market.name, quote.datetime
FROM market INNER JOIN
quote ON market.id = quote.code
WHERE quote.code in(72, 215,216,217,218,219,220)
) t1 ORDER BY quote.datetime DESC

[cansum396]

SELECT TOP 6 *
FROM (SELECT DISTINCT quote.code, market.name, quote.datetime
FROM market INNER JOIN
quote ON market.id = quote.code
WHERE quote.code in(72, 215,216,217,218,219,220)
) t1 ORDER BY datetime DESC

[cansum396]

用写的第二个就可以了

[lasker]

可以是可以 我的意图是让他选择出CODE值不重复的记录可是失败了？（选出了两条记录值都是72）

[lasker]

在此基础上要选出code是唯一的应该怎么写语句？

[fcuandy]

你用 distinct quote.code, market.name, quote.datetime 时，会按这三个列的组合去DISTINCT而不是按某一个列。
比如
aaa bbb ccc
aaa zzz xxx
两条记录都会被列出来。

SELECT TOP 6 quote.code, MAX(market.name), MAX(quote.datetime) mt /*或者MIN*/
FROM market
INNER JOIN
quote
ON market.id = quote.code
WHERE quote.code in(72, 215,216,217,218,219,220)
GROUP BY quote.code
ORDER BY mt DESC

[lasker]

果然 还是你厉害啊

[anison]

mark