Sql 在UNION查询中查找MIN

我有一张桌子，有三列:Price1、Price2和Price3.对于每个价格列，还有一个专用的金额列Amount t1、Amount t2和Amount t3. 还有列ID和批次.

我想做的是找到最小值all the three Amount columns combined.

以下是我现在使用的SQL

Select
MIN(Q.Min_Size)  As Min_Min_Size 
From
    (Select
         Min("Archive"."Amount1") As Min_Size
     From
         "Archive"
     Where
         "Archive"."ID" = '123' And
         "Archive"."Price1" = 7.4 And
         "Archive"."Batch" > 2986 And
         "Archive"."Batch" < 6243) Q
Union 
Select
    Q.Min_Size
From
    (Select
         Min("Archive"."Amount2") As Min_Size
     From
         "Archive"
     Where
         "Archive"."ID" = '123' And
         "Archive"."Price2" = 7.4 And
         "Archive"."Batch" > 2986 And
         "Archive"."Batch" < 6243) Q
Group By
    Q.Min_Size
Union 
Select
    Q.Min_Size
From
    (Select
         Min("Archive"."Amount3") As Min_Size
     From
         "Archive"
     Where
         "Archive"."ID" = '123' And
         "Archive"."Price3" = 7.4 And
         "Archive"."Batch" > 2986 And
         "Archive"."Batch" < 6243) Q
Group By
    Q.Min_Size

在这个语句中，我有三行，第一行最小的列是"Amount t1"，第二行的最小行是"Amount t2"，第三行的最小行是"Amount t3".相反，我想要达到的是one line only with the minimum of the three

EDIT个

我发现这个新说法很管用，但我想知道是否还有更好的说法.

Select
    Min(Least("Archive"."Amount1", "Archive"."Amount2", "Archive"."Amount3")) As MinAmount
From
    "Archive"
Where
    ("Archive"."ID" = '123' And
        "Archive"."Price1" = 7.4 And
        "Archive"."Batch" > 2986 And
        "Archive"."Batch" < 6243) Or
    ("Archive"."ID" = '123' And
        "Archive"."Batch" > 2986 And
        "Archive"."Batch" < 6243 And
        "Archive"."Price2" = 7.4) Or
    ("Archive"."ID" = '123' And
        "Archive"."Batch" > 2986 And
        "Archive"."Batch" < 6243 And
        "Archive"."Price3" = 7.4)