表：《半成品结存表》，《半成品入库表》，《半成品领用表
》，《客户退货表》

字段：材质、色号、规格、结存数量、入库数量、退货数量、领用数量。

SQL：

select 材质,规格,色号,结存数量, 0 as 入库数量,0 as 退货数量,0 as 领用数量 from 半成品结存表
union all select 材质,规格,色号,0 as 结存数量,入库数量,0 as 退货数量,0 as 领用数量 from 半成品入库表
UNION ALL select 材质,规格,色号,0 as 结存数量,0 as 入库数量,领用数量,0 as 退货数量 from 半成品领用表
UNION ALL select 材质,规格,色号,0 as 结存数量,0 as 入库数量,0 as 领用数量,退货数量 from 客户退货表;