根据SQL中另一个表中不同值的数量插入行

Question

我有一个包含PO＃，Days_to_travel和Days_warehouse字段的表。我将表中不同的Days_in_warehouse值插入到临时表中。我需要一个脚本，它将从Temp表中的Days_in_warehouse字段中的所有值插入到表1中的Days_in_warehouse_batch行中，复制PO记录，直到所有PO都有不同值的记录。 实施例： 温度表：（只包含一个场与表1中的所有不同的值）

Days_in_warehouse 
     20 
     30 
     40 

表1：

PO# Days_to_travel Days_in_warehouse Days_in_warehouse_batch 
1  10    20    
2   5    30 
3   7    40 

更新表1：

PO# Days_to_travel Days_in_warehouse Days_in_warehouse_batch 
1  10    20     20 
1  10    20     30 
1  10    20     40 
2   5    30     20 
2   5    30     30 
2   5    30     40 
3   7    40     20 
3   7    40     30 
3   7    40     40 

任何想法至于如何更新表1以查看期望的结果？

Answer 1

另一种方式没有TEMP表的d DELETE。

UPDATE T SET [Days_in_warehouse_batch] = [Days_in_warehouse]; 

INSERT INTO T ([PO], [Days_to_travel], 
       [Days_in_warehouse], [Days_in_warehouse_batch]) 
    SELECT T.PO, 
      T.Days_to_travel, 
      T.Days_in_warehouse, 
      DAYS_Table.Days_in_warehouse 
    FROM T 
    CROSS JOIN 
      (SELECT DISTINCT Days_in_warehouse FROM T) as DAYS_Table 
    WHERE T.Days_in_warehouse <> DAYS_Table.Days_in_warehouse; 

SQLFiddle demo

Answer 2

你要找的是两张表格之间的cartesian product。

select t1.po, t1.daystotravel, t1.daysinwarehouse, temp.daysinwarehousebatch 
from table1 t1, temp 

我能想到用这些值更新table1的最简单方法是插入它们，然后删除原件。

insert into table1  
select t1.po, t1.daystotravel, t1.daysinwarehouse, temp.daysinwarehousebatch 
from table1 t1, temp 

，然后删除原稿：

delete from table1 where daysinwarehousebatch is null 

• SQL Fiddle Demo

Answer 3

我建议如下：

insert into table1(PO#, Days_to_travel, Days_in_warehouse, Days_in_warehouse_batch) 
    select PO#, Days_to_travel, Days_in_warehouse, Days_in_warehouse 
    from table1 cross join 
     (select 20 as Days_in_warehouse union all select 30 union all select 40) var 
    where Days_in_warehouse_batch is null; 

delete from table1 
    where Days_in_warehouse_batch is null;