集合操作

SQL 集合操作将多个查询块的结果合并为单个结果。
SQL 标准定义了以下三种集合操作：UNION、INTERSECT、EXCEPT、UNION ALL、INTERSECT ALL、EXCEPT ALL。

Union

将两个查询块中的所有结果合并为一个结果，并省略任何重复项。

从 customers 和 users 表中获取所有不重复的名称。

import-pattern

builder-pattern

schema.ts

import { union } from 'drizzle-orm/mysql-core'
import { users, customers } from './schema'

const allNamesForUserQuery = db.select({ name: users.name }).from(users);

const result = await union(
	allNamesForUserQuery,
	db.select({ name: customers.name }).from(customers)
).limit(10);

(select `name` from `sellers`)
union
(select `name` from `customers`)
limit 10

import { users, customers } from './schema'

const result = await db
  .select({ name: users.name })
  .from(users)
  .union(db.select({ name: customers.name }).from(customers))
  .limit(10);

(select `name` from `sellers`)
union
(select `name` from `customers`)
limit 10

import { int, mysqlTable, text, varchar } from "drizzle-orm/mysql-core";

export const users = mysqlTable('sellers', {
    id: int().primaryKey(),
    name: varchar({ length: 256 }).notNull(),
    address: text(),
});

export const customers = mysqlTable('customers', {
    id: int().primaryKey(),
    name: varchar(, { length: 256 }).notNull(),
    city: text(),
    email: varchar({ length: 256 }).notNull()
});

Union All

将两个查询块中的所有结果合并为一个结果，并保留重复项。

假设你有两个表，一个代表在线销售，另一个代表门店销售。在这种情况下，你希望将这两个表中的数据合并为一个结果集。由于可能存在重复的交易，你希望保留所有记录，而不删除重复项。

import-pattern

builder-pattern

schema.ts

import { unionAll } from 'drizzle-orm/mysql-core'
import { onlineSales, inStoreSales } from './schema'

const onlineTransactions = db.select({ transaction: onlineSales.transactionId }).from(onlineSales);
const inStoreTransactions = db.select({ transaction: inStoreSales.transactionId }).from(inStoreSales);

const result = await unionAll(onlineTransactions, inStoreTransactions);

(select `transaction_id` from `online_sales`)
union all
(select `transaction_id` from `in_store_sales`)

import { onlineSales, inStoreSales } from './schema'

const result = await db
  .select({ transaction: onlineSales.transactionId })
  .from(onlineSales)
  .unionAll(
    db.select({ transaction: inStoreSales.transactionId }).from(inStoreSales)
  );

(select `transaction_id` from `online_sales`)
union all
(select `transaction_id` from `in_store_sales`)

import { int, mysqlTable, timestamp } from "drizzle-orm/mysql-core";

export const onlineSales = mysqlTable('online_sales', {
    transactionId: int('transaction_id').primaryKey(),
    productId: int('product_id').unique(),
    quantitySold: int('quantity_sold'),
    saleDate: timestamp('sale_date', { mode: 'date' }),
});

export const inStoreSales = mysqlTable('in_store_sales', {
    transactionId: int('transaction_id').primaryKey(),
    productId: int('product_id').unique(),
    quantitySold: int('quantity_sold'),
    saleDate: timestamp('sale_date', { mode: 'date' }),
});

交集

仅合并两个查询块结果中共有的那些行，并省略任何重复项。

假设你有两个存储学生课程选修信息的表。
你想找出两个不同院系之间共有的课程，
但你希望得到不同的课程名称，并且你不关心统计同一学生对同一课程的多次选修。

在这种情况下，你想找出两个院系之间共有的课程，但又不想
即使同一院系的多个学生都选修了同一课程，也将该课程计算多次。

import-pattern

builder-pattern

schema.ts

import { intersect } from 'drizzle-orm/mysql-core'
import { depA, depB } from './schema'

const departmentACourses = db.select({ courseName: depA.courseName }).from(depA);
const departmentBCourses = db.select({ courseName: depB.courseName }).from(depB);

const result = await intersect(departmentACourses, departmentBCourses);

(select `course_name` from `department_a_courses`)
intersect
(select `course_name` from `department_b_courses`)

import { depA, depB } from './schema'

const result = await db
  .select({ courseName: depA.courseName })
  .from(depA)
  .intersect(db.select({ courseName: depB.courseName }).from(depB));

(select `course_name` from `department_a_courses`)
intersect
(select `course_name` from `department_b_courses`)

import { int, mysqlTable, varchar } from "drizzle-orm/mysql-core";

export const depA = mysqlTable('department_a_courses', {
    studentId: int('student_id'),
    courseName: varchar('course_name', { length: 256 }).notNull(),
});

export const depB = mysqlTable('department_b_courses', {
    studentId: int('student_id'),
    courseName: varchar('course_name', { length: 256 }).notNull(),
});

交集全部

仅合并两个查询块结果中共有的那些行，并保留重复项。

让我们考虑这样一个场景：你有两个包含客户订单数据的表，想要识别既被普通客户又被 VIP 客户订购的产品。在这种情况下，你希望跟踪每个产品的数量，即使它被不同客户多次订购。

在这个场景中，你想找出既被普通客户又被 VIP 客户订购的产品，但即使同一个产品被不同客户多次订购，你也希望保留数量信息。

import-pattern

builder-pattern

schema.ts

import { intersectAll } from 'drizzle-orm/mysql-core'
import { regularCustomerOrders, vipCustomerOrders } from './schema'

const regularOrders = db.select({ 
    productId: regularCustomerOrders.productId,
    quantityOrdered: regularCustomerOrders.quantityOrdered }
).from(regularCustomerOrders);

const vipOrders = db.select({ 
    productId: vipCustomerOrders.productId,
    quantityOrdered: vipCustomerOrders.quantityOrdered }
).from(vipCustomerOrders);

const result = await intersectAll(regularOrders, vipOrders);

(select `product_id`, `quantity_ordered` from `regular_customer_orders`)
intersect all
(select `product_id`, `quantity_ordered` from `vip_customer_orders`)

import { regularCustomerOrders, vipCustomerOrders } from './schema'

const result = await db
    .select({
      productId: regularCustomerOrders.productId,
      quantityOrdered: regularCustomerOrders.quantityOrdered,
    })
    .from(regularCustomerOrders)
    .intersectAll(
      db
        .select({
          productId: vipCustomerOrders.productId,
          quantityOrdered: vipCustomerOrders.quantityOrdered,
        })
        .from(vipCustomerOrders)
    );

(select `product_id`, `quantity_ordered` from `regular_customer_orders`)
intersect all
(select `product_id`, `quantity_ordered` from `vip_customer_orders`)

import { int, mysqlTable } from "drizzle-orm/mysql-core";

export const regularCustomerOrders = mysqlTable('regular_customer_orders', {
    customerId: int('customer_id').primaryKey(),
    productId: int('product_id').notNull(),
    quantityOrdered: int('quantity_ordered').notNull(),
});

export const vipCustomerOrders = mysqlTable('vip_customer_orders', {
    customerId: int('customer_id').primaryKey(),
    productId: int('product_id').notNull(),
    quantityOrdered: int('quantity_ordered').notNull(),
});

Except

对于两个查询块 A 和 B，返回 A 中所有也不出现在 B 中的结果，并省略任何重复项。

假设你有两个表，用来存储员工项目分配的信息。
你想找出只属于一个部门、而不与另一个部门共享的项目，并排除重复项。

在这种情况下，你想识别那些只属于一个部门、且不与另一个部门共享的项目。你不希望对同一个项目
计算多次，即使同一部门中的多个员工被分配到了它。

import-pattern

builder-pattern

schema.ts

import { except } from 'drizzle-orm/mysql-core'
import { depA, depB } from './schema'

const departmentACourses = db.select({ courseName: depA.projectsName }).from(depA);
const departmentBCourses = db.select({ courseName: depB.projectsName }).from(depB);

const result = await except(departmentACourses, departmentBCourses);

(select `projects_name` from `department_a_projects`)
except
(select `projects_name` from `department_b_projects`)

import { depA, depB } from './schema'

const result = await db
    .select({ courseName: depA.projectsName })
    .from(depA)
    .except(db.select({ courseName: depB.projectsName }).from(depB));

(select `projects_name` from `department_a_projects`)
except
(select `projects_name` from `department_b_projects`)

import { int, mysqlTable, varchar } from "drizzle-orm/mysql-core";

export const depA = mysqlTable('department_a_projects', {
    employeeId: int('employee_id'),
    projectsName: varchar('projects_name', { length: 256 }).notNull(),
});

export const depB = mysqlTable('department_b_projects', {
    employeeId: int('employee_id'),
    projectsName: varchar('projects_name', { length: 256 }).notNull(),
});

Except All

对于两个查询块 A 和 B，返回 A 中所有不同时也出现在 B 中的结果，并保留重复项。

假设有两个包含客户订单数据的表，你想识别仅由普通客户下单的产品（不包括 VIP 客户）。在这种情况下，你希望跟踪每种产品的数量，即使它被不同的普通客户多次下单。

在这个场景中，你想找出仅由普通客户下单、而没有被 VIP 客户下单的产品。你希望保留数量信息，即使同一种产品被不同的普通客户多次下单。

import-pattern

builder-pattern

schema.ts

import { exceptAll } from 'drizzle-orm/mysql-core'
import { regularCustomerOrders, vipCustomerOrders } from './schema'

const regularOrders = db.select({ 
    productId: regularCustomerOrders.productId,
    quantityOrdered: regularCustomerOrders.quantityOrdered }
).from(regularCustomerOrders);

const vipOrders = db.select({ 
    productId: vipCustomerOrders.productId,
    quantityOrdered: vipCustomerOrders.quantityOrdered }
).from(vipCustomerOrders);

const result = await exceptAll(regularOrders, vipOrders);

(select `product_id`, `quantity_ordered` from `regular_customer_orders`)
except all
(select `product_id`, `quantity_ordered` from `vip_customer_orders`)

import { regularCustomerOrders, vipCustomerOrders } from './schema'

const result = await db
    .select({
      productId: regularCustomerOrders.productId,
      quantityOrdered: regularCustomerOrders.quantityOrdered,
    })
    .from(regularCustomerOrders)
    .exceptAll(
      db
        .select({
          productId: vipCustomerOrders.productId,
          quantityOrdered: vipCustomerOrders.quantityOrdered,
        })
        .from(vipCustomerOrders)
    );

(select `product_id`, `quantity_ordered` from `regular_customer_orders`)
except all
(select `product_id`, `quantity_ordered` from `vip_customer_orders`)

import { int, mysqlTable } from "drizzle-orm/mysql-core";

export const regularCustomerOrders = mysqlTable('regular_customer_orders', {
    customerId: int('customer_id').primaryKey(),
    productId: int('product_id').notNull(),
    quantityOrdered: int('quantity_ordered').notNull(),
});

export const vipCustomerOrders = mysqlTable('vip_customer_orders', {
    customerId: int('customer_id').primaryKey(),
    productId: int('product_id').notNull(),
    quantityOrdered: int('quantity_ordered').notNull(),
});