Find 选项

基础选项

所有存储库和管理器find方法都接受可用于查询所需数据的特殊选项，而无需使用QueryBuilder：

  • select - 表示必须选择对象的哪些属性
  1. userRepository.find({ select: ["firstName", "lastName"] });
  • relations - 关系需要加载主体。 也可以加载子关系（join 和 leftJoinAndSelect 的简写）
  1. userRepository.find({ relations: ["profile", "photos", "videos"] });
  2. userRepository.find({ relations: ["profile", "photos", "videos", "videos.video_attributes"] });
  • join - 需要为实体执行联接，扩展版对的”relations”。
  1. userRepository.find({
  2.     join: {
  3.         alias: "user",
  4.         leftJoinAndSelect: {
  5.             profile: "user.profile",
  6.             photo: "user.photos",
  7.             video: "user.videos"
  8.         }
  9.     }
  10. });
  • where -查询实体的简单条件。
  1. userRepository.find({ where: { firstName: "Timber", lastName: "Saw" } });

查询嵌入实体列应该根据定义它的层次结构来完成。 例：

  1. userRepository.find({ where: { name: { first: "Timber", last: "Saw" } } });

使用 OR 运算符查询：

  1. userRepository.find({
  2.     where: [{ firstName: "Timber", lastName: "Saw" }, { firstName: "Stan", lastName: "Lee" }]
  3. });

将执行以下查询：

  1. SELECT * FROM "user" WHERE ("firstName" = 'Timber' AND "lastName" = 'Saw') OR ("firstName" = 'Stan' AND "lastName" = 'Lee')
  • order - 选择排序
  1. userRepository.find({
  2.     order: {
  3.         name: "ASC",
  4.         id: "DESC"
  5.     }
  6. });

返回多个实体的find方法（find，findAndCount，findByIds），同时也接受以下选项：

  • skip - 偏移（分页）
  1. userRepository.find({
  2.     skip: 5
  3. });
  • take - limit (分页) - 得到的最大实体数。
  1. userRepository.find({
  2.     take: 10
  3. });

** 如果你正在使用带有 MSSQL 的 typeorm，并且想要使用take或limit，你必须正确使用 order，否则将会收到以下错误：'FETCH语句中NEXT选项的使用无效。'

  1. userRepository.find({
  2.     order: {
  3.         columnName: "ASC"
  4.     },
  5.     skip: 0,
  6.     take: 10
  7. });
  • cache - 启用或禁用查询结果缓存。 有关更多信息和选项，请参见caching。
  1. userRepository.find({
  2.     cache: true
  3. });
  • lock - 启用锁查询。 只能在findOne方法中使用。 lock是一个对象，可以定义为：
    1. { mode: "optimistic", version: number|Date }
    或者
    1. { mode: "pessimistic_read"|"pessimistic_write"|"dirty_read" }

例如:

  1. userRepository.findOne(1, {
  2.     lock: { mode: "optimistic", version: 1 }
  3. })

find 选项的完整示例：

  1. userRepository.find({
  2.     select: ["firstName", "lastName"],
  3.     relations: ["profile", "photos", "videos"],
  4.     where: {
  5.         firstName: "Timber",
  6.         lastName: "Saw"
  7.     },
  8.     order: {
  9.         name: "ASC",
  10.         id: "DESC"
  11.     },
  12.     skip: 5,
  13.     take: 10,
  14.     cache: true
  15. });

进阶选项

TypeORM 提供了许多内置运算符，可用于创建更复杂的查询：

  • Not
  1. import { Not } from "typeorm";
  3. const loadedPosts = await connection.getRepository(Post).find({
  4.     title: Not("About #1")
  5. });

将执行以下查询：

  1. SELECT * FROM "post" WHERE "title" != 'About #1'
  • LessThan
  1. import { LessThan } from "typeorm";
  3. const loadedPosts = await connection.getRepository(Post).find({
  4.     likes: LessThan(10)
  5. });

将执行以下查询：

  1. SELECT * FROM "post" WHERE "likes" < 10
  • LessThanOrEqual
  1. import { LessThanOrEqual } from "typeorm";
  2. const loadedPosts = await connection.getRepository(Post).find({
  3.     likes: LessThanOrEqual(10)
  4. });

将执行以下查询：

  1. SELECT * FROM "post" WHERE "likes" <= 10
  • MoreThan
  1. import { MoreThan } from "typeorm";
  3. const loadedPosts = await connection.getRepository(Post).find({
  4.     likes: MoreThan(10)
  5. });

将执行以下查询：

  1. SELECT * FROM "post" WHERE "likes" > 10
  • MoreThanOrEqual
  1. import { MoreThanOrEqual } from "typeorm";
  2. const loadedPosts = await connection.getRepository(Post).find({
  3.     likes: MoreThanOrEqual(10)
  4. });

将执行以下查询：

  1. SELECT * FROM "post" WHERE "likes" >= 10
  • Equal
  1. import { Equal } from "typeorm";
  3. const loadedPosts = await connection.getRepository(Post).find({
  4.     title: Equal("About #2")
  5. });

将执行以下查询：

  1. SELECT * FROM "post" WHERE "title" = 'About #2'
  • Like
  1. import { Like } from "typeorm";
  3. const loadedPosts = await connection.getRepository(Post).find({
  4.     title: Like("%out #%")
  5. });

将执行以下查询：

  1. SELECT * FROM "post" WHERE "title" LIKE '%out #%'
  • Between
  1. import { Between } from "typeorm";
  3. const loadedPosts = await connection.getRepository(Post).find({
  4.     likes: Between(1, 10)
  5. });

将执行以下查询：

  1. SELECT * FROM "post" WHERE "likes" BETWEEN 1 AND 10
  • In
  1. import { In } from "typeorm";
  3. const loadedPosts = await connection.getRepository(Post).find({
  4.     title: In(["About #2", "About #3"])
  5. });

将执行以下查询：

  1. SELECT * FROM "post" WHERE "title" IN ('About #2','About #3')
  • Any
  1. import { Any } from "typeorm";
  3. const loadedPosts = await connection.getRepository(Post).find({
  4.     title: Any(["About #2", "About #3"])
  5. });

将执行以下查询： (Postgres notation):

  1. SELECT * FROM "post" WHERE "title" = ANY(['About #2','About #3'])
  • IsNull
  1. import { IsNull } from "typeorm";
  3. const loadedPosts = await connection.getRepository(Post).find({
  4.     title: IsNull()
  5. });

将执行以下查询：

  1. SELECT * FROM "post" WHERE "title" IS NULL
  • Raw
  1. import { Raw } from "typeorm";
  3. const loadedPosts = await connection.getRepository(Post).find({
  4.     likes: Raw("1 + likes = 4")
  5. });

将执行以下查询：

  1. SELECT * FROM "post" WHERE 1 + "likes" = 4

注意：注意Raw操作符。 它应该从提供的表达式执行纯 SQL，而不能包含用户输入，否则将导致 SQL 注入。

你还可以将这些运算符与Not运算符组合使用：

  1. import { Not, MoreThan, Equal } from "typeorm";
  3. const loadedPosts = await connection.getRepository(Post).find({
  4.     likes: Not(MoreThan(10)),
  5.     title: Not(Equal("About #2"))
  6. });

将执行以下查询：

  1. SELECT * FROM "post" WHERE NOT("likes" > 10) AND NOT("title" = 'About #2')