我有3个表:PostgreSQL的选择查询不起作用
CREATE table materials
(id serial primary key not null,
name varchar(50) not null,
unit varchar(10) not null default 'шт',
price decimal(12, 2) not null check (price>0));
CREATE table warehouses
(id serial primary key not null,
lastname varchar(25) not null);
CREATE table materials_in_warehouses
(id_warehouses integer references warehouses(id) on update cascade on delete cascade,
id_materials integer references materials(id),
unit varchar(15) default 'шт',
count integer not null CHECK (count>0),
lastdate date not null,
primary key (id_warehouses, id_materials);
,我需要为每种材料选择:名字;仓库的计数,其中材料存在于我试图做这样的事情的> 100
量:
select materials.name, count(select * from materials_in_warehouses where
materials.id = materials_in_warehouses.id_materials AND material_in_warehouses.count > 100) as sount from materials;
当然不过,这种废话不能工作。
预先感谢您。
您的代码有错误或... – ashkufaraz
类型'materials.id'是串行的而'materials_in_warehouses.id_materials'是整数!? – ashkufaraz
@ashkufaraz序列就像mysql中的auto_increment。这是一个整数,但带有自动增量。它仍然是整数。 – AlexanderMP