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| author | muqiuhan <[email protected]> | 2025-09-09 06:17:00 +0000 |
|---|---|---|
| committer | muqiuhan <[email protected]> | 2025-09-09 06:17:00 +0000 |
| commit | d5de65fdb1802cdf498d65d93397f290813c377c (patch) | |
| tree | 92fe61a76d20d1203203665d4b48e7f151f088bd /2025/02 | |
| parent | 48efa2dfde7c263f84ee5bb0872747034908d607 (diff) | |
| download | blog-d5de65fdb1802cdf498d65d93397f290813c377c.tar.gz | |
deploy: 9665097f0fa0dae9f92123fac54d26c0818758a5
Diffstat (limited to '2025/02')
| -rw-r--r-- | 2025/02/10/实时搜索中的防抖函数/index.html | 14 | ||||
| -rw-r--r-- | 2025/02/11/从事件风暴看领域驱动设计/index.html | 20 | ||||
| -rw-r--r-- | 2025/02/18/Prisma-关系型数据库的-Self-relations/index.html | 26 | ||||
| -rw-r--r-- | 2025/02/19/Repository-pattern-in-Typescript/index.html | 16 |
4 files changed, 46 insertions, 30 deletions
diff --git a/2025/02/10/实时搜索中的防抖函数/index.html b/2025/02/10/实时搜索中的防抖函数/index.html index 4f9ecd38..2390de3e 100644 --- a/2025/02/10/实时搜索中的防抖函数/index.html +++ b/2025/02/10/实时搜索中的防抖函数/index.html @@ -193,18 +193,20 @@ </div> <div class="post-content"> <p>在实现实时搜索功能时，通常会使用输入框的事件监听器来捕获用户的输入变化，并在输入变化时发送搜索请求。为了避免过多的请求导致服务器负担过重，通常会使用“防抖”（debounce）技术来控制请求的频率。</p> -<h3 id="实现步骤"><a href="#实现步骤" class="headerlink" title="实现步骤"></a>实现步骤</h3><ol> +<h3 id="实现步骤"><a class="header-anchor" href="#实现步骤">¶</a>实现步骤</h3> +<ol> <li>监听输入框的变化：使用<code>input</code>事件监听器来捕获用户的输入变化。</li> <li>防抖处理：使用防抖函数来限制请求的频率。防抖函数会在用户停止输入一段时间后才发送请求。</li> <li>发送请求：在防抖函数中调用搜索请求。</li> </ol> -<h3 id="防抖函数示例"><a href="#防抖函数示例" class="headerlink" title="防抖函数示例"></a>防抖函数示例</h3><p>以下是一个简单的防抖函数示例：</p> +<h3 id="防抖函数示例"><a class="header-anchor" href="#防抖函数示例">¶</a>防抖函数示例</h3> +<p>以下是一个简单的防抖函数示例：</p> <figure class="highlight javascript"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">function</span> <span class="title function_">debounce</span>(<span class="params">func, wait</span>) {</span><br><span class="line"> <span class="keyword">let</span> timeout;</span><br><span class="line"> <span class="keyword">return</span> <span class="keyword">function</span>(<span class="params">...args</span>) {</span><br><span class="line"> <span class="keyword">const</span> context = <span class="variable language_">this</span>;</span><br><span class="line"> <span class="built_in">clearTimeout</span>(timeout);</span><br><span class="line"> timeout = <span class="built_in">setTimeout</span>(<span class="function">() =></span> func.<span class="title function_">apply</span>(context, args), wait);</span><br><span class="line"> };</span><br><span class="line">}</span><br></pre></td></tr></table></figure> - -<h3 id="实现实时搜索"><a href="#实现实时搜索" class="headerlink" title="实现实时搜索"></a>实现实时搜索</h3><p>假设你有一个输入框用于搜索患者：</p> +<h3 id="实现实时搜索"><a class="header-anchor" href="#实现实时搜索">¶</a>实现实时搜索</h3> +<p>假设你有一个输入框用于搜索患者：</p> <figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br><span class="line">37</span><br></pre></td><td class="code"><pre><span class="line"><script></span><br><span class="line"> import { onMount } from 'svelte';</span><br><span class="line"> import { patientsStore } from '$lib/stores/patients.svelte';</span><br><span class="line"></span><br><span class="line"> let searchTerm = '';</span><br><span class="line"></span><br><span class="line"> // 防抖函数</span><br><span class="line"> function debounce(func, wait) {</span><br><span class="line"> let timeout;</span><br><span class="line"> return function(...args) {</span><br><span class="line"> const context = this;</span><br><span class="line"> clearTimeout(timeout);</span><br><span class="line"> timeout = setTimeout(() => func.apply(context, args), wait);</span><br><span class="line"> };</span><br><span class="line"> }</span><br><span class="line"></span><br><span class="line"> // 搜索函数</span><br><span class="line"> const searchPatients = debounce(async (term) => {</span><br><span class="line"> if (term) {</span><br><span class="line"> // 发送搜索请求</span><br><span class="line"> const response = await fetch(`/api/search-patients?query=${term}`);</span><br><span class="line"> const data = await response.json();</span><br><span class="line"> patientsStore.mbglPatients = data;</span><br><span class="line"> } else {</span><br><span class="line"> // 清空搜索结果或恢复默认数据</span><br><span class="line"> patientsStore.mbglPatients = [];</span><br><span class="line"> }</span><br><span class="line"> }, 300); // 300ms 的防抖时间</span><br><span class="line"></span><br><span class="line"> // 监听输入框变化</span><br><span class="line"> function handleInput(event) {</span><br><span class="line"> searchTerm = event.target.value;</span><br><span class="line"> searchPatients(searchTerm);</span><br><span class="line"> }</span><br><span class="line"></script></span><br><span class="line"></span><br><span class="line"><input type="text" placeholder="搜索患者..." on:input={handleInput} bind:value={searchTerm} /></span><br></pre></td></tr></table></figure> - -<h3 id="请求发送间隔"><a href="#请求发送间隔" class="headerlink" title="请求发送间隔"></a>请求发送间隔</h3><ul> +<h3 id="请求发送间隔"><a class="header-anchor" href="#请求发送间隔">¶</a>请求发送间隔</h3> +<ul> <li>防抖时间：通常设置为 300ms 到 500ms 之间。这个时间足够让用户完成输入并减少不必要的请求。</li> <li>考虑用户体验：防抖时间过短可能导致过多请求，过长则可能让用户感到延迟。300ms 是一个常用的折中值。</li> </ul> diff --git a/2025/02/11/从事件风暴看领域驱动设计/index.html b/2025/02/11/从事件风暴看领域驱动设计/index.html index 7afb6836..3ef557ea 100644 --- a/2025/02/11/从事件风暴看领域驱动设计/index.html +++ b/2025/02/11/从事件风暴看领域驱动设计/index.html @@ -194,7 +194,25 @@ <div class="post-content"> <p>事件风暴（Event Storming）是一种领域驱动设计（DDD）的实践方法，由 Alberto Brandolini 提出，旨在通过团队协作的方式快速理解和建模业务领域。</p> <p>以下是事件风暴及相关领域驱动设计中的一些核心概念和知识点：</p> -<p>1. 领域（Domain）：指的是业务相关知识的集合，可以进一步划分为子域。<br>2. 子域（Subdomain）：是领域的一部分，可以是核心域、支撑域或通用域。<br>3. 核心域（Core Domain）：指领域中最核心的部分，通常对应企业的核心业务。<br>4. 通用语言（Ubiquitous Language）：团队所有成员使用的一种语言，用于确保业务和软件之间的沟通一致性。<br>5. 限界上下文（Bounded Context）：定义了一组规则和协议，用于明确领域模型的适用范围。<br>6. 实体（Entity）：具有唯一标识和生命周期的领域对象。<br>7. 值对象（Value Object）：描述了某种特性或属性的对象，没有概念标识。<br>8. 聚合（Aggregate）：一组相关对象的集合，由一个聚合根（Aggregate Root）统一管理。<br>9. 领域事件（Domain Event）：领域中发生的重要事件，可以用于通知其他领域对象或跨限界上下文进行解耦和协作。<br>10. 命令（Command）：表示要执行的操作，通常与事件一一对应。<br>11. 读模型（Read Model）：为了优化读取操作而设计的模型，可能与写模型不同。<br>12. 决策命令（Decision Command）：在事件风暴中，直接导致事件发生的命令。<br>13. 战略设计（Strategic Design）：高层次的抽象和归类，包括理清上下文和子域的划分。<br>14. 战术设计（Tactical Design）：对特定上下文下的模型进行详细设计，包括聚合、实体和值对象。<br>15. 贫血模型（Anemic Domain Model）：领域对象只有属性及其getter/setter方法的纯数据类，业务逻辑通过服务实现。<br>16. 充血模型（Rich Domain Model）：领域对象包含业务逻辑，每个对象都是活跃的。<br>17. 资源库（Repository）：用于检索和持久化领域对象的机制。<br>18. 服务（Service）：在模型中独立的操作，可以是领域服务或应用服务。<br>19. 固定规则（Invariant）：为设计元素做出的断言，必须一直保持为真。</p> +<p>1. 领域（Domain）：指的是业务相关知识的集合，可以进一步划分为子域。<br> +2. 子域（Subdomain）：是领域的一部分，可以是核心域、支撑域或通用域。<br> +3. 核心域（Core Domain）：指领域中最核心的部分，通常对应企业的核心业务。<br> +4. 通用语言（Ubiquitous Language）：团队所有成员使用的一种语言，用于确保业务和软件之间的沟通一致性。<br> +5. 限界上下文（Bounded Context）：定义了一组规则和协议，用于明确领域模型的适用范围。<br> +6. 实体（Entity）：具有唯一标识和生命周期的领域对象。<br> +7. 值对象（Value Object）：描述了某种特性或属性的对象，没有概念标识。<br> +8. 聚合（Aggregate）：一组相关对象的集合，由一个聚合根（Aggregate Root）统一管理。<br> +9. 领域事件（Domain Event）：领域中发生的重要事件，可以用于通知其他领域对象或跨限界上下文进行解耦和协作。<br> +10. 命令（Command）：表示要执行的操作，通常与事件一一对应。<br> +11. 读模型（Read Model）：为了优化读取操作而设计的模型，可能与写模型不同。<br> +12. 决策命令（Decision Command）：在事件风暴中，直接导致事件发生的命令。<br> +13. 战略设计（Strategic Design）：高层次的抽象和归类，包括理清上下文和子域的划分。<br> +14. 战术设计（Tactical Design）：对特定上下文下的模型进行详细设计，包括聚合、实体和值对象。<br> +15. 贫血模型（Anemic Domain Model）：领域对象只有属性及其getter/setter方法的纯数据类，业务逻辑通过服务实现。<br> +16. 充血模型（Rich Domain Model）：领域对象包含业务逻辑，每个对象都是活跃的。<br> +17. 资源库（Repository）：用于检索和持久化领域对象的机制。<br> +18. 服务（Service）：在模型中独立的操作，可以是领域服务或应用服务。<br> +19. 固定规则（Invariant）：为设计元素做出的断言，必须一直保持为真。</p> <p>事件风暴通常包括以下步骤：</p> <ul> <li>识别领域事件</li> diff --git a/2025/02/18/Prisma-关系型数据库的-Self-relations/index.html b/2025/02/18/Prisma-关系型数据库的-Self-relations/index.html index 0eac083b..0916a06e 100644 --- a/2025/02/18/Prisma-关系型数据库的-Self-relations/index.html +++ b/2025/02/18/Prisma-关系型数据库的-Self-relations/index.html @@ -195,8 +195,8 @@ <blockquote> <p>A relation field can also reference its own model, in this case the relation is called a <em>self-relation</em>. Self-relations can be of any cardinality, 1-1, 1-n and m-n.</p> </blockquote> -<h2 id="一对一"><a href="#一对一" class="headerlink" title="一对一"></a>一对一</h2><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br></pre></td><td class="code"><pre><span class="line">model User {</span><br><span class="line"> id Int @id @default(autoincrement())</span><br><span class="line"> name String?</span><br><span class="line"> successorId Int? @unique</span><br><span class="line"> successor User? @relation("BlogOwnerHistory", fields: [successorId], references: [id])</span><br><span class="line"> predecessor User? @relation("BlogOwnerHistory")</span><br><span class="line">}</span><br></pre></td></tr></table></figure> - +<h2 id="一对一"><a class="header-anchor" href="#一对一">¶</a>一对一</h2> +<figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br></pre></td><td class="code"><pre><span class="line">model User {</span><br><span class="line"> id Int @id @default(autoincrement())</span><br><span class="line"> name String?</span><br><span class="line"> successorId Int? @unique</span><br><span class="line"> successor User? @relation("BlogOwnerHistory", fields: [successorId], references: [id])</span><br><span class="line"> predecessor User? @relation("BlogOwnerHistory")</span><br><span class="line">}</span><br></pre></td></tr></table></figure> <p>User 展现了这样一个模型：</p> <ul> <li>User 可以有一个或零个前驱（predecessor）</li> @@ -214,9 +214,8 @@ </blockquote> <p>而在关系型数据库中，一对一的 self-relation 可以用如下 SQL 描述：</p> <figure class="highlight sql"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">CREATE TABLE</span> "User" (</span><br><span class="line"> id SERIAL <span class="keyword">PRIMARY KEY</span>,</span><br><span class="line"> "name" TEXT,</span><br><span class="line"> "successorId" <span class="type">INTEGER</span></span><br><span class="line">);</span><br><span class="line"></span><br><span class="line"><span class="keyword">ALTER TABLE</span> "User" <span class="keyword">ADD CONSTRAINT</span> fk_successor_user <span class="keyword">FOREIGN KEY</span> ("successorId") <span class="keyword">REFERENCES</span> "User" (id);</span><br><span class="line"></span><br><span class="line"><span class="keyword">ALTER TABLE</span> "User" <span class="keyword">ADD CONSTRAINT</span> successor_unique <span class="keyword">UNIQUE</span> ("successorId");</span><br></pre></td></tr></table></figure> - -<h2 id="一对多"><a href="#一对多" class="headerlink" title="一对多"></a>一对多</h2><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br></pre></td><td class="code"><pre><span class="line">model User {</span><br><span class="line"> id Int @id @default(autoincrement())</span><br><span class="line"> name String?</span><br><span class="line"> teacherId Int?</span><br><span class="line"> teacher User? @relation("TeacherStudents", fields: [teacherId], references: [id])</span><br><span class="line"> students User[] @relation("TeacherStudents")</span><br><span class="line">}</span><br></pre></td></tr></table></figure> - +<h2 id="一对多"><a class="header-anchor" href="#一对多">¶</a>一对多</h2> +<figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br></pre></td><td class="code"><pre><span class="line">model User {</span><br><span class="line"> id Int @id @default(autoincrement())</span><br><span class="line"> name String?</span><br><span class="line"> teacherId Int?</span><br><span class="line"> teacher User? @relation("TeacherStudents", fields: [teacherId], references: [id])</span><br><span class="line"> students User[] @relation("TeacherStudents")</span><br><span class="line">}</span><br></pre></td></tr></table></figure> <p>User 展现了这样一个模型：</p> <ul> <li>一个 User 只能有零个或一个 teacher</li> @@ -227,27 +226,26 @@ </blockquote> <p>用 SQL 描述 User model：</p> <figure class="highlight sql"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">CREATE TABLE</span> "User" (</span><br><span class="line"> id SERIAL <span class="keyword">PRIMARY KEY</span>,</span><br><span class="line"> "name" TEXT,</span><br><span class="line"> "teacherId" <span class="type">INTEGER</span></span><br><span class="line">);</span><br><span class="line"></span><br><span class="line"><span class="keyword">ALTER TABLE</span> "User" <span class="keyword">ADD CONSTRAINT</span> fk_teacherid_user <span class="keyword">FOREIGN KEY</span> ("teacherId") <span class="keyword">REFERENCES</span> "User" (id);</span><br></pre></td></tr></table></figure> - <p><code>teacherId</code> 没有使用 <code>UNIQUE</code> 约束，这代表着多个 students 可以有同一个 teacher</p> -<h2 id="多对多"><a href="#多对多" class="headerlink" title="多对多"></a>多对多</h2><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br></pre></td><td class="code"><pre><span class="line">model User {</span><br><span class="line"> id Int @id @default(autoincrement())</span><br><span class="line"> name String?</span><br><span class="line"> followedBy User[] @relation("UserFollows")</span><br><span class="line"> following User[] @relation("UserFollows")</span><br><span class="line">}</span><br></pre></td></tr></table></figure> - +<h2 id="多对多"><a class="header-anchor" href="#多对多">¶</a>多对多</h2> +<figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br></pre></td><td class="code"><pre><span class="line">model User {</span><br><span class="line"> id Int @id @default(autoincrement())</span><br><span class="line"> name String?</span><br><span class="line"> followedBy User[] @relation("UserFollows")</span><br><span class="line"> following User[] @relation("UserFollows")</span><br><span class="line">}</span><br></pre></td></tr></table></figure> <ul> <li>一个 User 可以被零个或多个 Users 关注</li> <li>一个 User 可以关注零个或多个 Users</li> </ul> <blockquote> -<p>对于关系型数据库，多对多的关系是隐式的，这意味着 Prisma ORM 会在底层数据库中维护一个 <a target="_blank" rel="noopener" href="https://www.prisma.io/docs/orm/prisma-schema/data-model/relations/many-to-many-relations#relation-tables">relation table</a>:<br>A relation table (also sometimes called a <em>JOIN</em>, <em>link</em> or <em>pivot</em> table) connects two or more other tables and therefore creates a <em>relation</em> between them. Creating relation tables is a common data modelling practice in SQL to represent relationships between different entities. In essence it means that “one m-n relation is modeled as two 1-n relations in the database”.</p> +<p>对于关系型数据库，多对多的关系是隐式的，这意味着 Prisma ORM 会在底层数据库中维护一个 <a target="_blank" rel="noopener" href="https://www.prisma.io/docs/orm/prisma-schema/data-model/relations/many-to-many-relations#relation-tables">relation table</a>:<br> +A relation table (also sometimes called a <em>JOIN</em>, <em>link</em> or <em>pivot</em> table) connects two or more other tables and therefore creates a <em>relation</em> between them. Creating relation tables is a common data modelling practice in SQL to represent relationships between different entities. In essence it means that “one m-n relation is modeled as two 1-n relations in the database”.</p> <p>We recommend using <a target="_blank" rel="noopener" href="https://www.prisma.io/docs/orm/prisma-schema/data-model/relations/many-to-many-relations#implicit-many-to-many-relations">implicit</a> m-n-relations, where Prisma ORM automatically generates the relation table in the underlying database. <a target="_blank" rel="noopener" href="https://www.prisma.io/docs/orm/prisma-schema/data-model/relations/many-to-many-relations#explicit-many-to-many-relations">Explicit</a> m-n-relations should be used when you need to store additional data in the relations, such as the date the relation was created.</p> </blockquote> <p>如果需要需要通过多对多的关系来保存其他字段，也可以创建<a target="_blank" rel="noopener" href="https://www.prisma.io/docs/orm/prisma-schema/data-model/relations/many-to-many-relations#explicit-many-to-many-relations">显式</a>的多对多 self 关系：</p> <figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br></pre></td><td class="code"><pre><span class="line">model User {</span><br><span class="line"> id Int @id @default(autoincrement())</span><br><span class="line"> name String?</span><br><span class="line"> followedBy Follows[] @relation("followedBy")</span><br><span class="line"> following Follows[] @relation("following")</span><br><span class="line">}</span><br><span class="line"></span><br><span class="line">model Follows {</span><br><span class="line"> followedBy User @relation("followedBy", fields: [followedById], references: [id])</span><br><span class="line"> followedById Int</span><br><span class="line"> following User @relation("following", fields: [followingId], references: [id])</span><br><span class="line"> followingId Int</span><br><span class="line"></span><br><span class="line"> @@id([followingId, followedById])</span><br><span class="line">}</span><br></pre></td></tr></table></figure> - <p>在关系型数据库中，可以用如下 SQL 描述:</p> <figure class="highlight sql"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">CREATE TABLE</span> "User" (</span><br><span class="line"> id <span class="type">integer</span> <span class="keyword">DEFAULT</span> nextval(<span class="string">'"User_id_seq"'</span>::regclass) <span class="keyword">PRIMARY KEY</span>,</span><br><span class="line"> name text</span><br><span class="line">);</span><br><span class="line"><span class="keyword">CREATE TABLE</span> "_UserFollows" (</span><br><span class="line"> "A" <span class="type">integer</span> <span class="keyword">NOT NULL</span> <span class="keyword">REFERENCES</span> "User"(id) <span class="keyword">ON</span> <span class="keyword">DELETE</span> CASCADE <span class="keyword">ON</span> <span class="keyword">UPDATE</span> CASCADE,</span><br><span class="line"> "B" <span class="type">integer</span> <span class="keyword">NOT NULL</span> <span class="keyword">REFERENCES</span> "User"(id) <span class="keyword">ON</span> <span class="keyword">DELETE</span> CASCADE <span class="keyword">ON</span> <span class="keyword">UPDATE</span> CASCADE</span><br><span class="line">);</span><br></pre></td></tr></table></figure> - -<h2 id="在同一模型上建立多个-self-relations"><a href="#在同一模型上建立多个-self-relations" class="headerlink" title="在同一模型上建立多个 self-relations"></a>在同一模型上建立多个 self-relations</h2><figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br></pre></td><td class="code"><pre><span class="line">model User {</span><br><span class="line"> id Int @id @default(autoincrement())</span><br><span class="line"> name String?</span><br><span class="line"> teacherId Int?</span><br><span class="line"> teacher User? @relation("TeacherStudents", fields: [teacherId], references: [id])</span><br><span class="line"> students User[] @relation("TeacherStudents")</span><br><span class="line"> followedBy User[] @relation("UserFollows")</span><br><span class="line"> following User[] @relation("UserFollows")</span><br><span class="line">}</span><br></pre></td></tr></table></figure> - -<h2 id="REFS"><a href="#REFS" class="headerlink" title="REFS."></a>REFS.</h2><ul> +<h2 id="在同一模型上建立多个-self-relations"><a class="header-anchor" href="#在同一模型上建立多个-self-relations">¶</a>在同一模型上建立多个 self-relations</h2> +<figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br></pre></td><td class="code"><pre><span class="line">model User {</span><br><span class="line"> id Int @id @default(autoincrement())</span><br><span class="line"> name String?</span><br><span class="line"> teacherId Int?</span><br><span class="line"> teacher User? @relation("TeacherStudents", fields: [teacherId], references: [id])</span><br><span class="line"> students User[] @relation("TeacherStudents")</span><br><span class="line"> followedBy User[] @relation("UserFollows")</span><br><span class="line"> following User[] @relation("UserFollows")</span><br><span class="line">}</span><br></pre></td></tr></table></figure> +<h2 id="REFS"><a class="header-anchor" href="#REFS">¶</a>REFS.</h2> +<ul> <li><a target="_blank" rel="noopener" href="https://www.prisma.io/docs/orm/prisma-schema/data-model/relations#relation-fields">fully annotated</a></li> <li><a target="_blank" rel="noopener" href="https://www.prisma.io/docs/orm/prisma-schema/data-model/models#optional-and-mandatory-fields">required</a></li> <li><a target="_blank" rel="noopener" href="https://www.prisma.io/docs/orm/prisma-schema/data-model/relations/many-to-many-relations#implicit-many-to-many-relations">implicit</a></li> diff --git a/2025/02/19/Repository-pattern-in-Typescript/index.html b/2025/02/19/Repository-pattern-in-Typescript/index.html index c0753a94..99250448 100644 --- a/2025/02/19/Repository-pattern-in-Typescript/index.html +++ b/2025/02/19/Repository-pattern-in-Typescript/index.html @@ -198,30 +198,28 @@ <p>抽象化数据访问层的主要作用是将应用的业务逻辑与对数据库的数据访问等实现细节进行解耦。DB 框架的更改不应该影响到应用程序的核心服务，并且它们应该对业务逻辑代码透明。</p> <p>业务服务应该只依赖于抽象，而不是实现，数据服务同理。</p> <hr> -<h1 id="Intro"><a href="#Intro" class="headerlink" title="Intro."></a>Intro.</h1><p>例如，此时有一个书籍存储的微服务，并且有一个“添加新书籍”的操作用例，在此用例中可以通过使用 <code>Book</code> 这个 <em>Repository</em> 来添加新书籍，而 <code>Book</code> 具体使用什么数据库，怎么存并不是业务需要关心的事情。</p> -<h2 id="具体实现方式"><a href="#具体实现方式" class="headerlink" title="具体实现方式"></a>具体实现方式</h2><p>假设有以下实体类型定义：</p> +<h1>Intro.</h1> +<p>例如，此时有一个书籍存储的微服务，并且有一个“添加新书籍”的操作用例，在此用例中可以通过使用 <code>Book</code> 这个 <em>Repository</em> 来添加新书籍，而 <code>Book</code> 具体使用什么数据库，怎么存并不是业务需要关心的事情。</p> +<h2 id="具体实现方式"><a class="header-anchor" href="#具体实现方式">¶</a>具体实现方式</h2> +<p>假设有以下实体类型定义：</p> <figure class="highlight typescript"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">export</span> <span class="keyword">class</span> <span class="title class_">Author</span> {</span><br><span class="line"> <span class="attr">firstName</span>: <span class="built_in">string</span>;</span><br><span class="line"> <span class="attr">lastName</span>: <span class="built_in">string</span>;</span><br><span class="line">}</span><br><span class="line"></span><br><span class="line"><span class="keyword">export</span> <span class="keyword">class</span> <span class="title class_">Genre</span> {</span><br><span class="line"> <span class="attr">name</span>: <span class="built_in">string</span>;</span><br><span class="line">}</span><br><span class="line"></span><br><span class="line"><span class="keyword">export</span> <span class="keyword">class</span> <span class="title class_">Book</span> {</span><br><span class="line"> <span class="attr">title</span>: <span class="built_in">string</span>;</span><br><span class="line"> <span class="attr">author</span>: <span class="title class_">Author</span>;</span><br><span class="line"> <span class="attr">genre</span>: <span class="title class_">Genre</span>;</span><br><span class="line"> <span class="attr">publishDate</span>: <span class="title class_">Date</span>;</span><br><span class="line">}</span><br></pre></td></tr></table></figure> - -<h3 id="抽象化"><a href="#抽象化" class="headerlink" title="抽象化"></a>抽象化</h3><p>第一步是抽象化出一个通用的 <em>Repository</em> ，其中包含通用的操作：</p> +<h3 id="抽象化"><a class="header-anchor" href="#抽象化">¶</a>抽象化</h3> +<p>第一步是抽象化出一个通用的 <em>Repository</em> ，其中包含通用的操作：</p> <figure class="highlight typescript"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">export</span> <span class="keyword">abstract</span> <span class="keyword">class</span> <span class="title class_">IGenericRepository</span><T> {</span><br><span class="line"> <span class="keyword">abstract</span> <span class="title function_">getAll</span>(): <span class="title class_">Promise</span><T[]>;</span><br><span class="line"></span><br><span class="line"> <span class="keyword">abstract</span> <span class="title function_">get</span>(<span class="attr">id</span>: <span class="built_in">string</span>): <span class="title class_">Promise</span><T>;</span><br><span class="line"></span><br><span class="line"> <span class="keyword">abstract</span> <span class="title function_">create</span>(<span class="attr">item</span>: T): <span class="title class_">Promise</span><T>;</span><br><span class="line"></span><br><span class="line"> <span class="keyword">abstract</span> <span class="title function_">update</span>(<span class="attr">id</span>: <span class="built_in">string</span>, <span class="attr">item</span>: T);</span><br><span class="line">}</span><br></pre></td></tr></table></figure> - <ul> <li>这里具体有那些函数可以根据需要（业务）自己定义。</li> <li>类型参数 <code>T</code> 表示每个实体。</li> </ul> -<p>接着，定义一个数据服务，其中包含使用 <code>IGenericRepositoiry</code> 定义的具体实例对应的 _Repository_：</p> +<p>接着，定义一个数据服务，其中包含使用 <code>IGenericRepositoiry</code> 定义的具体实例对应的 <em>Repository</em>：</p> <figure class="highlight typescript"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">import</span> { <span class="title class_">Author</span>, <span class="title class_">Book</span>, <span class="title class_">Genre</span> } <span class="keyword">from</span> <span class="string">'../entities'</span>;</span><br><span class="line"><span class="keyword">import</span> { <span class="title class_">IGenericRepository</span> } <span class="keyword">from</span> <span class="string">'./generic-repository.abstract'</span>;</span><br><span class="line"></span><br><span class="line"><span class="keyword">export</span> <span class="keyword">abstract</span> <span class="keyword">class</span> <span class="title class_">IDataServices</span> {</span><br><span class="line"> <span class="keyword">abstract</span> <span class="attr">authors</span>: <span class="title class_">IGenericRepository</span><<span class="title class_">Author</span>>;</span><br><span class="line"></span><br><span class="line"> <span class="keyword">abstract</span> <span class="attr">books</span>: <span class="title class_">IGenericRepository</span><<span class="title class_">Book</span>>;</span><br><span class="line"></span><br><span class="line"> <span class="keyword">abstract</span> <span class="attr">genres</span>: <span class="title class_">IGenericRepository</span><<span class="title class_">Genre</span>>;</span><br><span class="line">}</span><br></pre></td></tr></table></figure> - <ul> <li>这里有三个 <em>Repository</em> 分别对应不同的实体。</li> <li><code>IGenericRepository</code> 中定义的函数是每个 <em>Repository</em> 公开的通用存储函数。</li> </ul> <p>以上这些就是对业务中的实体的 <em>Repository</em> 抽象，这样就隔离开了业务和存储逻辑，例如使用 MongoDB，可以实现一个 <code>MongoGenericRepository</code>：</p> <figure class="highlight typescript"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">import</span> { <span class="title class_">Model</span> } <span class="keyword">from</span> <span class="string">'mongoose'</span>;</span><br><span class="line"><span class="keyword">import</span> { <span class="title class_">IGenericRepository</span> } <span class="keyword">from</span> <span class="string">'../../../core'</span>;</span><br><span class="line"></span><br><span class="line"><span class="keyword">export</span> <span class="keyword">class</span> <span class="title class_">MongoGenericRepository</span><T> <span class="keyword">implements</span> <span class="title class_">IGenericRepository</span><T> {</span><br><span class="line"> <span class="keyword">private</span> <span class="attr">_repository</span>: <span class="title class_">Model</span><T>;</span><br><span class="line"> <span class="keyword">private</span> <span class="attr">_populateOnFind</span>: <span class="built_in">string</span>[];</span><br><span class="line"></span><br><span class="line"> <span class="title function_">constructor</span>(<span class="params"><span class="attr">repository</span>: <span class="title class_">Model</span><T>, <span class="attr">populateOnFind</span>: <span class="built_in">string</span>[] = []</span>) {</span><br><span class="line"> <span class="variable language_">this</span>.<span class="property">_repository</span> = repository;</span><br><span class="line"> <span class="variable language_">this</span>.<span class="property">_populateOnFind</span> = populateOnFind;</span><br><span class="line"> }</span><br><span class="line"></span><br><span class="line"> <span class="title function_">getAll</span>(): <span class="title class_">Promise</span><T[]> {</span><br><span class="line"> <span class="keyword">return</span> <span class="variable language_">this</span>.<span class="property">_repository</span>.<span class="title function_">find</span>().<span class="title function_">populate</span>(<span class="variable language_">this</span>.<span class="property">_populateOnFind</span>).<span class="title function_">exec</span>();</span><br><span class="line"> }</span><br><span class="line"></span><br><span class="line"> <span class="title function_">get</span>(<span class="attr">id</span>: <span class="built_in">any</span>): <span class="title class_">Promise</span><T> {</span><br><span class="line"> <span class="keyword">return</span> <span class="variable language_">this</span>.<span class="property">_repository</span>.<span class="title function_">findById</span>(id).<span class="title function_">populate</span>(<span class="variable language_">this</span>.<span class="property">_populateOnFind</span>).<span class="title function_">exec</span>();</span><br><span class="line"> }</span><br><span class="line"></span><br><span class="line"> <span class="title function_">create</span>(<span class="attr">item</span>: T): <span class="title class_">Promise</span><T> {</span><br><span class="line"> <span class="keyword">return</span> <span class="variable language_">this</span>.<span class="property">_repository</span>.<span class="title function_">create</span>(item);</span><br><span class="line"> }</span><br><span class="line"></span><br><span class="line"> <span class="title function_">update</span>(<span class="params"><span class="attr">id</span>: <span class="built_in">string</span>, <span class="attr">item</span>: T</span>) {</span><br><span class="line"> <span class="keyword">return</span> <span class="variable language_">this</span>.<span class="property">_repository</span>.<span class="title function_">findByIdAndUpdate</span>(id, item);</span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure> - <p>然后实现一个 <code>MongoDataServices</code>:</p> <figure class="highlight typescript"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br><span class="line">37</span><br><span class="line">38</span><br><span class="line">39</span><br><span class="line">40</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">import</span> { <span class="title class_">Injectable</span>, <span class="title class_">OnApplicationBootstrap</span> } <span class="keyword">from</span> <span class="string">'@nestjs/common'</span>;</span><br><span class="line"><span class="keyword">import</span> { <span class="title class_">InjectModel</span> } <span class="keyword">from</span> <span class="string">'@nestjs/mongoose'</span>;</span><br><span class="line"><span class="keyword">import</span> { <span class="title class_">Model</span> } <span class="keyword">from</span> <span class="string">'mongoose'</span>;</span><br><span class="line"><span class="keyword">import</span> { <span class="title class_">IDataServices</span> } <span class="keyword">from</span> <span class="string">'../../../core'</span>;</span><br><span class="line"><span class="keyword">import</span> { <span class="title class_">MongoGenericRepository</span> } <span class="keyword">from</span> <span class="string">'./mongo-generic-repository'</span>;</span><br><span class="line"><span class="keyword">import</span> {</span><br><span class="line"> <span class="title class_">Author</span>,</span><br><span class="line"> <span class="title class_">AuthorDocument</span>,</span><br><span class="line"> <span class="title class_">Book</span>,</span><br><span class="line"> <span class="title class_">BookDocument</span>,</span><br><span class="line"> <span class="title class_">Genre</span>,</span><br><span class="line"> <span class="title class_">GenreDocument</span>,</span><br><span class="line">} <span class="keyword">from</span> <span class="string">'./model'</span>;</span><br><span class="line"></span><br><span class="line"><span class="meta">@Injectable</span>()</span><br><span class="line"><span class="keyword">export</span> <span class="keyword">class</span> <span class="title class_">MongoDataServices</span></span><br><span class="line"> <span class="keyword">implements</span> <span class="title class_">IDataServices</span>, <span class="title class_">OnApplicationBootstrap</span></span><br><span class="line">{</span><br><span class="line"> <span class="attr">authors</span>: <span class="title class_">MongoGenericRepository</span><<span class="title class_">Author</span>>;</span><br><span class="line"> <span class="attr">books</span>: <span class="title class_">MongoGenericRepository</span><<span class="title class_">Book</span>>;</span><br><span class="line"> <span class="attr">genres</span>: <span class="title class_">MongoGenericRepository</span><<span class="title class_">Genre</span>>;</span><br><span class="line"></span><br><span class="line"> <span class="title function_">constructor</span>(<span class="params"></span></span><br><span class="line"><span class="params"> <span class="meta">@InjectModel</span>(Author.name)</span></span><br><span class="line"><span class="params"> <span class="keyword">private</span> <span class="title class_">AuthorRepository</span>: <span class="title class_">Model</span><<span class="title class_">AuthorDocument</span>>,</span></span><br><span class="line"><span class="params"> <span class="meta">@InjectModel</span>(Book.name)</span></span><br><span class="line"><span class="params"> <span class="keyword">private</span> <span class="title class_">BookRepository</span>: <span class="title class_">Model</span><<span class="title class_">BookDocument</span>>,</span></span><br><span class="line"><span class="params"> <span class="meta">@InjectModel</span>(Genre.name)</span></span><br><span class="line"><span class="params"> <span class="keyword">private</span> <span class="title class_">GenreRepository</span>: <span class="title class_">Model</span><<span class="title class_">GenreDocument</span>>,</span></span><br><span class="line"><span class="params"> </span>) {}</span><br><span class="line"></span><br><span class="line"> <span class="title function_">onApplicationBootstrap</span>(<span class="params"></span>) {</span><br><span class="line"> <span class="variable language_">this</span>.<span class="property">authors</span> = <span class="keyword">new</span> <span class="title class_">MongoGenericRepository</span><<span class="title class_">Author</span>>(<span class="variable language_">this</span>.<span class="property">AuthorRepository</span>);</span><br><span class="line"> <span class="variable language_">this</span>.<span class="property">books</span> = <span class="keyword">new</span> <span class="title class_">MongoGenericRepository</span><<span class="title class_">Book</span>>(<span class="variable language_">this</span>.<span class="property">BookRepository</span>, [</span><br><span class="line"> <span class="string">'author'</span>,</span><br><span class="line"> <span class="string">'genre'</span>,</span><br><span class="line"> ]);</span><br><span class="line"> <span class="variable language_">this</span>.<span class="property">genres</span> = <span class="keyword">new</span> <span class="title class_">MongoGenericRepository</span><<span class="title class_">Genre</span>>(<span class="variable language_">this</span>.<span class="property">GenreRepository</span>);</span><br><span class="line"> }</span><br><span class="line">}</span><br></pre></td></tr></table></figure> - <hr> <p>Sunday, March 30, 2025 7:58 PM:</p> <p>感觉以上全错，不应该过度抽象 Repository 的，就让它分散在各个模块中，还可以参考 <a target="_blank" rel="noopener" href="https://github.com/Papooch/nestjs-cls">https://github.com/Papooch/nestjs-cls</a> 实现不会抽象泄漏的事务性 Repository 方法。</p> |