某工厂的物资管理系统涉及的实体有： 仓库：属性有仓库号、面积、电话号码 零件：属性有零件号、名称、单价 供应商：属性有供应商号、姓名、地址、电话 项目：属性有项目号、预算、开工日期 职工：属性有职工号、姓名、年龄 其中，一个仓库可以存放多种零件，一种零件可以存放在多个仓库中，用库存量来表示某种零件在某个仓库中的数量。一个仓库有多个职工当仓库保管员，一个职工只能在一个仓库工作。 供应商、项目和零件三者之间具有多对多的联系。即一个供应商可以供给若干项目多种零件，每个项目可以使用不同供应商供应的零件，写出sql语句

以下是涉及到的实体及其属性：

- 仓库：仓库号（warehouse_id）、面积（area）、电话号码（phone）
- 零件：零件号（part_id）、名称（name）、单价（price）
- 供应商：供应商号（supplier_id）、姓名（name）、地址（address）、电话（phone）
- 项目：项目号（project_id）、预算（budget）、开工日期（start_date）
- 职工：职工号（employee_id）、姓名（name）、年龄（age）

根据题目要求，可以得到以下表格：

- 仓库表（warehouse）：warehouse_id、area、phone
- 零件表（part）：part_id、name、price
- 供应商表（supplier）：supplier_id、name、address、phone
- 项目表（project）：project_id、budget、start_date
- 职工表（employee）：employee_id、name、age、warehouse_id

此外，还需要一张关联表来表示供应商、项目和零件之间的联系：

- 供应商-项目-零件关联表（supplier_project_part）：supplier_id、project_id、part_id

以下是针对题目要求的 SQL 语句：

1. 创建表格

CREATE TABLE warehouse (
  warehouse_id INT PRIMARY KEY,
  area FLOAT,
  phone VARCHAR(20)
);

CREATE TABLE part (
  part_id INT PRIMARY KEY,
  name VARCHAR(50),
  price FLOAT
);

CREATE TABLE supplier (
  supplier_id INT PRIMARY KEY,
  name VARCHAR(50),
  address VARCHAR(100),
  phone VARCHAR(20)
);

CREATE TABLE project (
  project_id INT PRIMARY KEY,
  budget FLOAT,
  start_date DATE
);

CREATE TABLE employee (
  employee_id INT PRIMARY KEY,
  name VARCHAR(50),
  age INT,
  warehouse_id INT,
  FOREIGN KEY (warehouse_id) REFERENCES warehouse (warehouse_id)
);

CREATE TABLE supplier_project_part (
  supplier_id INT,
  project_id INT,
  part_id INT,
  PRIMARY KEY (supplier_id, project_id, part_id),
  FOREIGN KEY (supplier_id) REFERENCES supplier (supplier_id),
  FOREIGN KEY (project_id) REFERENCES project (project_id),
  FOREIGN KEY (part_id) REFERENCES part (part_id)
);

2. 插入数据

INSERT INTO warehouse (warehouse_id, area, phone) VALUES (1, 1000, '123456789');
INSERT INTO warehouse (warehouse_id, area, phone) VALUES (2, 2000, '987654321');

INSERT INTO part (part_id, name, price) VALUES (1, '零件A', 10);
INSERT INTO part (part_id, name, price) VALUES (2, '零件B', 20);

INSERT INTO supplier (supplier_id, name, address, phone) VALUES (1, '供应商A', '地址A', '111111111');
INSERT INTO supplier (supplier_id, name, address, phone) VALUES (2, '供应商B', '地址B', '222222222');

INSERT INTO project (project_id, budget, start_date) VALUES (1, 1000000, '2022-01-01');
INSERT INTO project (project_id, budget, start_date) VALUES (2, 2000000, '2022-02-01');

INSERT INTO employee (employee_id, name, age, warehouse_id) VALUES (1, '职工A', 30, 1);
INSERT INTO employee (employee_id, name, age, warehouse_id) VALUES (2, '职工B', 40, 2);

INSERT INTO supplier_project_part (supplier_id, project_id, part_id) VALUES (1, 1, 1);
INSERT INTO supplier_project_part (supplier_id, project_id, part_id) VALUES (1, 1, 2);
INSERT INTO supplier_project_part (supplier_id, project_id, part_id) VALUES (2, 2, 2);

3. 查询某个仓库中所有零件及其库存量

SELECT part.name, COALESCE(SUM(inventory.quantity), 0) as inventory_count
FROM part
LEFT JOIN inventory ON part.part_id = inventory.part_id
WHERE inventory.warehouse_id = 1
GROUP BY part.part_id;

4. 查询某个零件在哪些仓库中存放，以及其库存量

SELECT warehouse.warehouse_id, warehouse.area, COALESCE(inventory.quantity, 0) as inventory_count
FROM warehouse
LEFT JOIN inventory ON warehouse.warehouse_id = inventory.warehouse_id AND inventory.part_id = 1;

5. 查询项目预算超过 100 万元的供应商姓名和地址

SELECT supplier.name, supplier.address
FROM supplier
INNER JOIN supplier_project_part ON supplier.supplier_id = supplier_project_part.supplier_id
INNER JOIN project ON supplier_project_part.project_id = project.project_id
WHERE project.budget > 1000000;

6. 查询所有职工的姓名和所在仓库的电话号码

SELECT employee.name, warehouse.phone
FROM employee
INNER JOIN warehouse ON employee.warehouse_id = warehouse.warehouse_id;