查询性能

说到 Drizzle - 我们在 SQL 之上构建了一个精简的 TypeScript 层，开销几乎为零。为了使其真正为零，你可以使用我们的预处理语句 API。

在数据库上运行查询时，会发生以下几件事：

查询构建器的所有配置都已连接到 SQL 字符串。
该字符串和参数将发送到数据库驱动程序
驱动程序将 SQL 查询编译为二进制 SQL 可执行格式并将其发送到数据库。

使用准备好的语句，你只需在 Drizzle ORM 端执行一次 SQL 连接，然后数据库驱动程序就可以重用预编译的二进制 SQL，而不必一直解析查询。它在大型 SQL 查询中具有极大的性能优势。

不同的数据库驱动程序以不同的方式支持预处理语句，有时，如果你使用 Drizzle ORM，则可以使用 比 better-sqlite3 驱动程序更快.。

准备好的语句

PostgreSQL

MySQL

SQLite

SingleStore

const db = drizzle(...);

const prepared = db.select().from(customers).prepare("statement_name");

const res1 = await prepared.execute();
const res2 = await prepared.execute();
const res3 = await prepared.execute();

const db = drizzle(...);

const prepared = db.select().from(customers).prepare();

const res1 = await prepared.execute();
const res2 = await prepared.execute();
const res3 = await prepared.execute();

const db = drizzle(...);

const prepared = db.select().from(customers).prepare();

const res1 = await prepared.execute();
const res2 = await prepared.execute();
const res3 = await prepared.execute();

占位符

当你需要嵌入动态运行时值时 - 你可以使用 sql.placeholder(...) API

PostgreSQL

MySQL

SQLite

SingleStore

import { sql } from "drizzle-orm";

const p1 = db
  .select()
  .from(customers)
  .where(eq(customers.id, sql.placeholder('id')))
  .prepare("p1")

await p1.execute({ id: 10 }) // SELECT * FROM customers WHERE id = 10
await p1.execute({ id: 12 }) // SELECT * FROM customers WHERE id = 12

const p2 = db
  .select()
  .from(customers)
  .where(sql`lower(${customers.name}) like ${sql.placeholder('name')}`)
  .prepare("p2");

await p2.execute({ name: '%an%' }) // SELECT * FROM customers WHERE name ilike '%an%'

import { sql } from "drizzle-orm";

const p1 = db
  .select()
  .from(customers)
  .where(eq(customers.id, sql.placeholder('id')))
  .prepare()

await p1.execute({ id: 10 }) // SELECT * FROM customers WHERE id = 10
await p1.execute({ id: 12 }) // SELECT * FROM customers WHERE id = 12

const p2 = db
  .select()
  .from(customers)
  .where(sql`lower(${customers.name}) like ${sql.placeholder('name')}`)
  .prepare();

await p2.execute({ name: '%an%' }) // SELECT * FROM customers WHERE name ilike '%an%'

import { sql } from "drizzle-orm";

const p1 = db
  .select()
  .from(customers)
  .where(eq(customers.id, sql.placeholder('id')))
  .prepare()

p1.get({ id: 10 }) // SELECT * FROM customers WHERE id = 10
p1.get({ id: 12 }) // SELECT * FROM customers WHERE id = 12

const p2 = db
  .select()
  .from(customers)
  .where(sql`lower(${customers.name}) like ${sql.placeholder('name')}`)
  .prepare();

p2.all({ name: '%an%' }) // SELECT * FROM customers WHERE name ilike '%an%'

import { sql } from "drizzle-orm";

const p1 = db
  .select()
  .from(customers)
  .where(eq(customers.id, sql.placeholder('id')))
  .prepare()

await p1.execute({ id: 10 }) // SELECT * FROM customers WHERE id = 10
await p1.execute({ id: 12 }) // SELECT * FROM customers WHERE id = 12

const p2 = db
  .select()
  .from(customers)
  .where(sql`lower(${customers.name}) like ${sql.placeholder('name')}`)
  .prepare();

await p2.execute({ name: '%an%' }) // SELECT * FROM customers WHERE name ilike '%an%'