我有一個包含以下特征的表：
我有一個包含以下特征的表：
Month (INT64)
COP (FLOAT64)
USD (FLOAT64)
EUR (FLOAT64)
ARS (FLOAT64)
CLP (FLOAT64)
便士 (FLOAT64)
MXN (FLOAT64)
此表包含了幾種貨幣與USD的匯率。
生成此表的查詢如下：
SELECT
CAST(MonthNum as INT64) as Month,
CAST(COP as FLOAT64) as COP。
CAST(USD as FLOAT64) as USD。
CAST(EUR as FLOAT64) as EUR。
CAST(ARS as FLOAT64) as ARS。
CAST(CLP as FLOAT64) asCLP,
CAST(PEN as FLOAT64) as PEN。
CAST(MXN as FLOAT64) as MXN。
FROM `xxx.region.xr.
`xxx.region.xr`。
WHERE[/span
= 'INTRA'型別
ORDER BY
Month DESC
這里有一個例子：
我想檢索相同的列，但條件是MAX(Month)，這是，所有的列，但僅僅是最大的月份，更大的MonthNum。 我是SQL的新手，我發現MAX()函式不能在WHERE條件下使用。我怎樣才能做到這一點呢？
uj5u.com熱心網友回復：
簡單的LIMIT 1如何呢
SELECT。
CAST(MonthNum as INT64) as Month,
CAST(COP as FLOAT64) as COP。
CAST(USD as FLOAT64) as USD。
CAST(EUR as FLOAT64) as EUR。
CAST(ARS as FLOAT64) as ARS。
CAST(CLP as FLOAT64) asCLP,
CAST(PEN as FLOAT64) as PEN。
CAST(MXN as FLOAT64) as MXN。
FROM `xxx.regional.xr`.
WHERE Type='INTRA'
ORDER BY Month DESC
LIMIT1
uj5u.com熱心網友回復：
使用子查詢:
SELECT
CAST(MonthNum as INT64) as Month,
CAST(COP as FLOAT64) as COP。
CAST(USD as FLOAT64) as USD。
CAST(EUR as FLOAT64) as EUR。
CAST(ARS as FLOAT64) as ARS。
CAST(CLP as FLOAT64) asCLP,
CAST(PEN as FLOAT64) as PEN。
CAST(MXN as FLOAT64) as MXN。
FROM `xxx.regional.xr`.
WHERE Type='INTRA'
AND MonthNum IN (SELECT MAX(MonthNum) FROM `xxx.regional.xr`)
ORDER BY Month DESC
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