Find 选项
- Find 选项
- 基础选项

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

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）

userRepository.find({ relations: ["profile", "photos", "videos"] });
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”。

userRepository.find({
    join: {
        alias: "user",
        leftJoinAndSelect: {
            profile: "user.profile",
            photo: "user.photos",
            video: "user.videos"
        }
    }
});

where -查询实体的简单条件。

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：

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

使用 OR 运算符查询：

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

将执行以下查询：

SELECT * FROM "user" WHERE ("firstName" = 'Timber' AND "lastName" = 'Saw') OR ("firstName" = 'Stan' AND "lastName" = 'Lee')

order - 选择排序

userRepository.find({
    order: {
        name: "ASC",
        id: "DESC"
    }
});

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）

userRepository.find({
    skip: 5
});

take - limit (分页) - 得到的最大实体数。

userRepository.find({
    take: 10
});

** 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。'

userRepository.find({
    order: {
        columnName: "ASC"
    },
    skip: 0,
    take: 10
});

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。

userRepository.find({
    cache: true
});

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： { mode: "optimistic", version: number|Date } 或者 ``` { mode: "pessimistic_read"|"pessimistic_write"|"dirty_read" }


例如:

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


find 选项的完整示例：

userRepository.find({ select: ["firstName", "lastName"], relations: ["profile", "photos", "videos"], where: { firstName: "Timber", lastName: "Saw" }, order: { name: "ASC", id: "DESC" }, skip: 5, take: 10, cache: true });


## 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`

import { Not } from "typeorm";

const loadedPosts = await connection.getRepository(Post).find({ title: Not("About #1") });


将执行以下查询：

SELECT * FROM "post" WHERE "title" != 'About #1'


  * `LessThan`

import { LessThan } from "typeorm";

const loadedPosts = await connection.getRepository(Post).find({ likes: LessThan(10) });


将执行以下查询：

SELECT * FROM "post" WHERE "likes" < 10


  * `LessThanOrEqual`

import { LessThanOrEqual } from "typeorm"; const loadedPosts = await connection.getRepository(Post).find({ likes: LessThanOrEqual(10) });


将执行以下查询：

SELECT * FROM "post" WHERE "likes" <= 10


  * `MoreThan`

import { MoreThan } from "typeorm";

const loadedPosts = await connection.getRepository(Post).find({ likes: MoreThan(10) });


将执行以下查询：

SELECT * FROM "post" WHERE "likes" > 10


  * `MoreThanOrEqual`

import { MoreThanOrEqual } from "typeorm"; const loadedPosts = await connection.getRepository(Post).find({ likes: MoreThanOrEqual(10) });


将执行以下查询：

SELECT * FROM "post" WHERE "likes" >= 10


  * `Equal`

import { Equal } from "typeorm";

const loadedPosts = await connection.getRepository(Post).find({ title: Equal("About #2") });


将执行以下查询：

SELECT * FROM "post" WHERE "title" = 'About #2'


  * `Like`

import { Like } from "typeorm";

const loadedPosts = await connection.getRepository(Post).find({ title: Like("%out #%") });


将执行以下查询：

SELECT * FROM "post" WHERE "title" LIKE '%out #%'


  * `Between`

import { Between } from "typeorm";

const loadedPosts = await connection.getRepository(Post).find({ likes: Between(1, 10) });


将执行以下查询：

SELECT * FROM "post" WHERE "likes" BETWEEN 1 AND 10


  * `In`

import { In } from "typeorm";

const loadedPosts = await connection.getRepository(Post).find({ title: In(["About #2", "About #3"]) });


将执行以下查询：

SELECT * FROM "post" WHERE "title" IN ('About #2','About #3')


  * `Any`

import { Any } from "typeorm";

const loadedPosts = await connection.getRepository(Post).find({ title: Any(["About #2", "About #3"]) });


将执行以下查询： (Postgres notation):

SELECT * FROM "post" WHERE "title" = ANY(['About #2','About #3'])


  * `IsNull`

import { IsNull } from "typeorm";

const loadedPosts = await connection.getRepository(Post).find({ title: IsNull() });


将执行以下查询：

SELECT * FROM "post" WHERE "title" IS NULL


  * `Raw`

import { Raw } from "typeorm";

const loadedPosts = await connection.getRepository(Post).find({ likes: Raw("1 + likes = 4") });


将执行以下查询：

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：

import { Not, MoreThan, Equal } from "typeorm";

const loadedPosts = await connection.getRepository(Post).find({ likes: Not(MoreThan(10)), title: Not(Equal("About #2")) });


将执行以下查询：

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