Question

SQL新手，我想创建一个结合两个表的新表。我试图使用插入选择查询来创建一个新表。所以假设以下

Jan Table

    C_ID      Total_Amount
      1           10
      2            3
      3            5

2月表

    C_ID      Total_Amount
     1            4
     4            22
     5            6

我想要决赛桌

    C_ID       Jan_Amount          Feb_Amount
     1             10                  4
     2             3                   0
     3             5                   0
     4             0                   22
     5             0                   6

我的SQL语句是

insert into Final 
    select Jan.C_ID, Jan.Total_Amount, Feb.Total_amount
    from Jan 
    full outer join Feb on Jan.C_ID = Feb.C_ID

问题在于，当我执行select Jan.C_ID时，它不会包含来自Feb表的客户ID 4和5。

解决此问题的正确方法是什么？

Answer 1

你可以使用联合所有例如：

加入表格alos

  insert into Final 
  select C_ID, ifnull(jan_Total_Amount,0), ifnull(feb_Total_amount,0)f
  from (

  select Jan.C_ID, Jan.Total_Amount as jan_Total_Amount, null as feb_Total_amount
  from jan
  union all
  select fed.C_ID, null, feb.Total_Amount
  from feb
    ) t

为了获得相同C_ID的两个值，你可以使用（假）聚合函数和分组

  insert into Final 
  select C_ID, min(jan_Total_Amount), feb_Total_amount
  from (
  select C_ID, ifnull(jan_Total_Amount,0) jan_Total_Amount , ifnull(feb_Total_amount,0) feb_Total_amount
  from (

  select Jan.C_ID, Jan.Total_Amount as jan_Total_Amount, null as feb_Total_amount
  from jan
  union all
  select fed.C_ID, null, feb.Total_Amount
  from feb
    ) t
  )t2 
  group by C_ID

Answer 2

您可以left join

申请right join和Union

insert into Table_3 (C_ID,Jan_Amount, Feb_Amount)
select T1.C_ID,T1.Total_Amount, T2.Total_Amount from Jan T1 left join Feb T2 ON T1.C_ID = T2.C_ID
UNION
select T2.C_ID,T1.Total_Amount, T2.Total_Amount from Jan T1 right join Feb T2 ON T1.C_ID = T2.C_ID
where T1.C_ID is null

sql join和insert

2 个答案: