SELECT
A.材料编号,
A.规格,
sum(A.数量)
FROM
(select 材料编号,规格,数量=sum(数量)*2 from table1 group by 材料编号,规格
union all
select 材料编号,规格,数量=sum(数量)*2 from table2 group by 材料编号,规格
union all
select 材料编号,规格,数量=sum(数量)*2 from table3 group by 材料编号,规格) A
GROUP BY
A.材料编号, A.规格
A.材料编号,
A.规格,
sum(A.数量)
FROM
(select 材料编号,规格,数量=sum(数量)*2 from table1 group by 材料编号,规格
union all
select 材料编号,规格,数量=sum(数量)*2 from table2 group by 材料编号,规格
union all
select 材料编号,规格,数量=sum(数量)*2 from table3 group by 材料编号,规格) A
GROUP BY
A.材料编号, A.规格
A.材料编号,
A.规格,
数量=sum(A.数量)
FROM
(select 材料编号,规格,数量=数量*2 from table1
union all
select 材料编号,规格,数量=数量*2 from table2
union all
select 材料编号,规格,数量=数量*2 from table3) A
GROUP BY
A.材料编号, A.规格
FROM (select 材料编号,规格,sum(数量)*2 as 数量 from table1
union all
select 材料编号,规格,sum(数量)*2 from table2
union all
select 材料编号,规格,sum(数量)*2 from table3
) A
GROUP BY A.材料编号, A.规格
--或者
SELECT 材料编号, 规格, sum(数量)*2 as 数量
FROM (select 材料编号,规格,sum(数量) as 数量 from table1
union all
select 材料编号,规格,sum(数量) from table2
union all
select 材料编号,规格,sum(数量) from table3
) A
GROUP BY A.材料编号, A.规格
A.材料编号,
A.规格,
数量=sum(A.数量)
FROM
(select 材料编号,规格,数量=数量*2 from table1
union all
select 材料编号,规格,数量=数量*2 from table2
union all
select 材料编号,规格,数量=数量*2 from table3) A
GROUP BY
A.材料编号, A.规格