视图

PostgreSQL
SQLite
MySQL
SingleStore

你可以通过多种方式使用 Drizzle ORM 声明视图。

你可以声明需要创建的视图，也可以声明数据库中已存在的视图。

你可以使用内联 query builder 语法、standalone query builder 和原始 sql 运算符声明视图语句。

使用内联或独立查询构建器创建视图时，视图列的模式将自动推断，但使用 sql 时，你必须明确声明视图列的模式。

声明视图

PostgreSQL
MySQL
SQLite
schema.ts
import { pgTable, pgView, serial, text, timestamp } from "drizzle-orm/pg-core";

export const user = pgTable("user", {
  id: serial(),
  name: text(),
  email: text(),
  password: text(),
  role: text().$type<"admin" | "customer">(),
  createdAt: timestamp("created_at"),
  updatedAt: timestamp("updated_at"),
});

export const userView = pgView("user_view").as((qb) => qb.select().from(user));
export const customersView = pgView("customers_view").as((qb) => qb.select().from(user).where(eq(user.role, "customer")));
CREATE VIEW "user_view" AS SELECT * FROM "user";
CREATE VIEW "customers_view" AS SELECT * FROM "user" WHERE "role" = 'customer';

如果你需要列的子集，你可以在查询构建器中使用 .select({ ... }) 方法，如下所示：

export const customersView = pgView("customers_view").as((qb) => {
  return qb
    .select({
      id: user.id,
      name: user.name,
      email: user.email,
    })
    .from(user);
});
CREATE VIEW "customers_view" AS SELECT "id", "name", "email" FROM "user" WHERE "role" = 'customer';

你也可以使用 standalone query builder 声明视图，其工作方式完全相同：

PostgreSQL
MySQL
SQLite
schema.ts
import { pgTable, pgView, serial, text, timestamp, QueryBuilder} from "drizzle-orm/pg-core";

const qb = new QueryBuilder();

export const user = pgTable("user", {
  id: serial(),
  name: text(),
  email: text(),
  password: text(),
  role: text().$type<"admin" | "customer">(),
  createdAt: timestamp("created_at"),
  updatedAt: timestamp("updated_at"),
});

export const userView = pgView("user_view").as(qb.select().from(user));
export const customersView = pgView("customers_view").as(qb.select().from(user).where(eq(user.role, "customer")));
CREATE VIEW "user_view" AS SELECT * FROM "user";
CREATE VIEW "customers_view" AS SELECT * FROM "user" WHERE "role" = 'customer';

使用原始 SQL 声明视图

当你需要使用查询构建器不支持的语法声明视图时，你可以直接使用 sql 运算符并明确指定视图列的模式。

// regular view
const newYorkers = pgView('new_yorkers', {
  id: serial('id').primaryKey(),
  name: text('name').notNull(),
  cityId: integer('city_id').notNull(),
}).as(sql`select * from ${users} where ${eq(users.cityId, 1)}`);

// materialized view
const newYorkers = pgMaterializedView('new_yorkers', {
  id: serial('id').primaryKey(),
  name: text('name').notNull(),
  cityId: integer('city_id').notNull(),
}).as(sql`select * from ${users} where ${eq(users.cityId, 1)}`);

声明现有视图

当你获得对数据库中现有视图的只读访问权限时，你应该使用 .existing() 视图配置，drizzle-kit 将忽略该配置，并且不会在生成的迁移中生成 create view 语句。

export const user = pgTable("user", {
  id: serial(),
  name: text(),
  email: text(),
  password: text(),
  role: text().$type<"admin" | "customer">(),
  createdAt: timestamp("created_at"),
  updatedAt: timestamp("updated_at"),
});

// regular view
export const trimmedUser = pgView("trimmed_user", {
  id: serial("id"),
  name: text("name"),
  email: text("email"),
}).existing();

// materialized view won't make any difference, yet you can use it for consistency
export const trimmedUser = pgMaterializedView("trimmed_user", {
  id: serial("id"),
  name: text("name"),
  email: text("email"),
}).existing();

物化视图

PostgreSQL
MySQL
SQLite

根据官方文档，PostgreSQL 同时提供 regular 和 materialized 视图。

PostgreSQL 中的物化视图片视图一样使用规则系统，但将结果以类似表的形式保存。

Drizzle ORM 原生支持 PostgreSQL 物化视图：

schema.ts
const newYorkers = pgMaterializedView('new_yorkers').as((qb) => qb.select().from(users).where(eq(users.cityId, 1)));
CREATE MATERIALIZED VIEW "new_yorkers" AS SELECT * FROM "users";

然后，你可以在应用运行时刷新物化视图：

await db.refreshMaterializedView(newYorkers);

await db.refreshMaterializedView(newYorkers).concurrently();

await db.refreshMaterializedView(newYorkers).withNoData();

扩展示例

查询中的所有参数都将被内联，而不是被 $1、$2 等替换。

// regular view
const newYorkers = pgView('new_yorkers')
  .with({
    checkOption: 'cascaded',
    securityBarrier: true,
    securityInvoker: true,
  })
  .as((qb) => {
    const sq = qb
      .$with('sq')
      .as(
        qb.select({ userId: users.id, cityId: cities.id })
          .from(users)
          .leftJoin(cities, eq(cities.id, users.homeCity))
          .where(sql`${users.age1} > 18`),
      );
    return qb.with(sq).select().from(sq).where(sql`${users.homeCity} = 1`);
  });

// materialized view
const newYorkers2 = pgMaterializedView('new_yorkers')
  .using('btree')
  .with({
    fillfactor: 90,
    toast_tuple_target: 0.5,
    autovacuum_enabled: true,
    ...
  })
  .tablespace('custom_tablespace')
  .withNoData()
  .as((qb) => {
    const sq = qb
      .$with('sq')
      .as(
        qb.select({ userId: users.id, cityId: cities.id })
          .from(users)
          .leftJoin(cities, eq(cities.id, users.homeCity))
          .where(sql`${users.age1} > 18`),
      );
    return qb.with(sq).select().from(sq).where(sql`${users.homeCity} = 1`);
  });