用于从两个表中查找总和的 SQL 查询

Question

我有两个表都具有用于标识相应行的序列 ID。 但是一张表以一对多的形式输入数据，而另一张表以一对一的形式输入数据。 我需要找到与特定序列 ID 对应的值的总和。

桌子就像

表格1

seq_id      amt1      amt2
  222        0         100 
  223        0         200
  224       300         0

表2

seq_id     code       amt3
 222        001        100
 222        002        150
 223        001        100

我需要从两个表中找到对应 id 的 amt1+amt2+amt3 的总和

即输出可能看起来像

总金额
850

Answer 1

这将显示表 1 中显示的所有 seq_id 值的总和

select t1.seq_id, sum(t1.amt1 + t1.amt2 + coalesce(t2.amt3)) as total_amount
from table1 t1
  left join table2 t2 on t1.seq_id = t2.seq_id
group by t1.seq_id;

如果表 2 中的 seq_id 值不在表 1 中，则需要完整的外连接。 在这种情况下，您还需要处理 t1 中的空值：

select t1.seq_id, sum(coalesce(t1.amt1,0) + coalesce(t1.amt2,0) + coalesce(t2.amt3)) as total_amount
from table1 t1
  full join table2 t2 on t1.seq_id = t2.seq_id
group by t1.seq_id;

如果要独立于 seq_id 对所有值求和，请使用联合：

select sum(amount) as total_amount
from (
   select amt1 + amt2 as amount
   from table1
   union all
   select amt3 as amount
   from table2
) t

Answer 2

几个嵌套查询应该可以解决问题：

SELECT a.seq_id, a_sum + b_sum AS total_sum
FROM   (SELECT   seq_id, amt1 + amt2 AS a_sum
        FROM     table1) a -- no GROUP BY, as seq_id is unique in this table
JOIN   (SELECT   seq_id, SUM(amt3) AS b_sum
        FROM     table2
        GROUP BY seq_id) b ON a.seq_id = b.seq_id

Answer 3

declare @table1 table (seq_id INT, amt1 decimal(18,2), amt2 decimal(18,2))
declare @table2 table (seq_id INT, code INT, amt3 decimal(18,2))
insert into @table1(seq_id, amt1, amt2)
values
(222 , 0 , 100),
(223 , 0 , 200),
(224 , 300, 0)

insert into @table2(seq_id, code, amt3)
values
(222 , 001 , 100),
(222 , 002 , 150),
(223 , 001 , 100)

select distinct
   t1.seq_id,
   t1.amt1 + t1.amt2 + t2.amt3
from @table1 t1
   join @table2 t2 on t2.seq_id = t1.seq_id

select SUM(t1.amt1) + SUM(t1.amt2) + SUM(t2.amt3)
from @table1 t1
   join @table2 t2 on t2.seq_id = t1.seq_id

Answer 4

尝试使用JOIN以下查询

SELECT IFNULL(a.amt1,0) + IFNULL(a.amt2,0) + IFNULL(b.amt3,0) as total_amount 
FROM table1 a JOIN table2 b 
ON a.seq_id=b.seq_id

Answer 5

我想出了更简单的

SELECT 
(SELECT SUM(atm1) FROM table1)+
(SELECT SUM(amt2) FROM table1)+
(SELECT SUM(amt3) FROM table2)
AS remain

Answer 6

用这个

select table1.seq_id, sum(table1.amt1 + table1.amt2 + coalesce(table2.amt3)) as total_amount
from table1
  left join table2 on table1.seq_id = table2.seq_id
group by table1.seq_id;