自定义SQL

何时使用自定义SQL

基本配置

#[derive(Entity)]
#[entity(table = "posts", schema = "blog", sql = "trait")]
pub struct Post {
 #[id]
 pub id: Uuid,
 #[field(create, update, response)]
 pub title: String,
 #[field(create, response)]
 pub author_id: Uuid,
 #[auto]
 #[field(response)]
 pub created_at: DateTime<Utc>,
}

实现Repository

use async_trait::async_trait;
use sqlx::PgPool;
#[async_trait]
impl PostRepository for PgPool {
 type Error = sqlx::Error;
 async fn create(&self, dto: CreatePostRequest) -> Result<Post, Self::Error> {
 let entity = Post::from(dto);
 let insertable = InsertablePost::from(&entity);
 sqlx::query(
 r#"
 INSERT INTO blog.posts (id, title, author_id, created_at)
 VALUES (1,ドル 2,ドル 3,ドル 4ドル)
 "#
 )
 .bind(insertable.id)
 .bind(&insertable.title)
 .bind(insertable.author_id)
 .bind(insertable.created_at)
 .execute(self)
 .await?;
 Ok(entity)
 }
 async fn find_by_id(&self, id: Uuid) -> Result<Option<Post>, Self::Error> {
 let row: Option<PostRow> = sqlx::query_as(
 "SELECT id, title, author_id, created_at FROM blog.posts WHERE id = 1ドル"
 )
 .bind(&id)
 .fetch_optional(self)
 .await?;
 Ok(row.map(Post::from))
 }
 async fn update(&self, id: Uuid, dto: UpdatePostRequest) -> Result<Post, Self::Error> {
 // 你的自定义更新逻辑
 todo!()
 }
 async fn delete(&self, id: Uuid) -> Result<bool, Self::Error> {
 let result = sqlx::query("DELETE FROM blog.posts WHERE id = 1ドル")
 .bind(&id)
 .execute(self)
 .await?;
 Ok(result.rows_affected() > 0)
 }
 async fn list(&self, limit: i64, offset: i64) -> Result<Vec<Post>, Self::Error> {
 let rows: Vec<PostRow> = sqlx::query_as(
 "SELECT id, title, author_id, created_at FROM blog.posts ORDER BY created_at DESC LIMIT 1ドル OFFSET 2ドル"
 )
 .bind(limit)
 .bind(offset)
 .fetch_all(self)
 .await?;
 Ok(rows.into_iter().map(Post::from).collect())
 }
}

示例:带作者Join的文章

// 带作者数据的扩展响应
pub struct PostWithAuthor {
 pub post: Post,
 pub author: User,
}
// 自定义repository扩展
pub trait PostRepositoryExt: PostRepository {
 async fn find_with_author(&self, id: Uuid) -> Result<Option<PostWithAuthor>, Self::Error>;
 async fn list_with_authors(&self, limit: i64, offset: i64) -> Result<Vec<PostWithAuthor>, Self::Error>;
}
#[async_trait]
impl PostRepositoryExt for PgPool {
 async fn find_with_author(&self, id: Uuid) -> Result<Option<PostWithAuthor>, Self::Error> {
 let row = sqlx::query_as::<_, (PostRow, UserRow)>(
 r#"
 SELECT
 p.id, p.title, p.author_id, p.created_at,
 u.id, u.username, u.email, u.created_at
 FROM blog.posts p
 JOIN auth.users u ON u.id = p.author_id
 WHERE p.id = 1ドル
 "#
 )
 .bind(&id)
 .fetch_optional(self)
 .await?;
 Ok(row.map(|(p, u)| PostWithAuthor {
 post: Post::from(p),
 author: User::from(u),
 }))
 }
 async fn list_with_authors(&self, limit: i64, offset: i64) -> Result<Vec<PostWithAuthor>, Self::Error> {
 // 类似的带join和分页的查询
 todo!()
 }
}

示例:全文搜索

pub trait PostSearchRepository {
 async fn search(&self, query: &str, limit: i64) -> Result<Vec<Post>, sqlx::Error>;
}
#[async_trait]
impl PostSearchRepository for PgPool {
 async fn search(&self, query: &str, limit: i64) -> Result<Vec<Post>, sqlx::Error> {
 let rows: Vec<PostRow> = sqlx::query_as(
 r#"
 SELECT id, title, author_id, created_at
 FROM blog.posts
 WHERE to_tsvector('english', title || ' ' || content) @@ plainto_tsquery('english', 1ドル)
 ORDER BY ts_rank(to_tsvector('english', title || ' ' || content), plainto_tsquery('english', 1ドル)) DESC
 LIMIT 2ドル
 "#
 )
 .bind(query)
 .bind(limit)
 .fetch_all(self)
 .await?;
 Ok(rows.into_iter().map(Post::from).collect())
 }
}

示例:软删除

#[derive(Entity)]
#[entity(table = "posts", sql = "trait")]
pub struct Post {
 #[id]
 pub id: Uuid,
 #[field(create, update, response)]
 pub title: String,
 #[field(response)]
 pub deleted_at: Option<DateTime<Utc>>,
 #[auto]
 #[field(response)]
 pub created_at: DateTime<Utc>,
}
#[async_trait]
impl PostRepository for PgPool {
 // ... 其他方法
 async fn delete(&self, id: Uuid) -> Result<bool, Self::Error> {
 // 软删除而不是硬删除
 let result = sqlx::query(
 "UPDATE blog.posts SET deleted_at = NOW() WHERE id = 1ドル AND deleted_at IS NULL"
 )
 .bind(&id)
 .execute(self)
 .await?;
 Ok(result.rows_affected() > 0)
 }
 async fn list(&self, limit: i64, offset: i64) -> Result<Vec<Post>, Self::Error> {
 // 排除已软删除的记录
 let rows: Vec<PostRow> = sqlx::query_as(
 r#"
 SELECT id, title, deleted_at, created_at
 FROM blog.posts
 WHERE deleted_at IS NULL
 ORDER BY created_at DESC
 LIMIT 1ドル OFFSET 2ドル
 "#
 )
 .bind(limit)
 .bind(offset)
 .fetch_all(self)
 .await?;
 Ok(rows.into_iter().map(Post::from).collect())
 }
}
// 管理员的额外方法
pub trait PostAdminRepository {
 async fn restore(&self, id: Uuid) -> Result<bool, sqlx::Error>;
 async fn hard_delete(&self, id: Uuid) -> Result<bool, sqlx::Error>;
 async fn list_deleted(&self, limit: i64, offset: i64) -> Result<Vec<Post>, sqlx::Error>;
}

示例:乐观锁

#[derive(Entity)]
#[entity(table = "documents", sql = "trait")]
pub struct Document {
 #[id]
 pub id: Uuid,
 #[field(create, update, response)]
 pub content: String,
 #[field(response)]
 pub version: i64,
 #[auto]
 #[field(response)]
 pub updated_at: DateTime<Utc>,
}
#[derive(Debug)]
pub enum DocumentError {
 Sqlx(sqlx::Error),
 ConcurrentModification,
}
#[async_trait]
impl DocumentRepository for PgPool {
 type Error = DocumentError;
 async fn update(&self, id: Uuid, dto: UpdateDocumentRequest) -> Result<Document, Self::Error> {
 // 需要当前版本用于乐观锁
 let expected_version = dto.version.ok_or(DocumentError::ConcurrentModification)?;
 let row: Option<DocumentRow> = sqlx::query_as(
 r#"
 UPDATE documents
 SET content = COALESCE(1,ドル content),
 version = version + 1,
 updated_at = NOW()
 WHERE id = 2ドル AND version = 3ドル
 RETURNING id, content, version, updated_at
 "#
 )
 .bind(&dto.content)
 .bind(&id)
 .bind(expected_version)
 .fetch_optional(self)
 .await
 .map_err(DocumentError::Sqlx)?;
 row.map(Document::from)
 .ok_or(DocumentError::ConcurrentModification)
 }
 // ... 其他方法
}

自定义SQL最佳实践

另见