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use crate::schema::posts::{published, title};
use crate::schema::posts::dsl::posts;
use crate::models::{NewPost, Post};
use diesel::pg::PgConnection;
use diesel::prelude::*;
use dotenvy::dotenv;
use std::env;
// 获取数据库连接
pub fn db_establish_connection() -> PgConnection {
dotenv().ok();
let database_url = env::var("DATABASE_URL").expect("DATABASE_URL must be set");
PgConnection::establish(&database_url)
.unwrap_or_else(|_| panic!("Error connecting to {}", database_url))
}
// 增加NewPost数据
pub fn db_create_post(connection: &mut PgConnection, blog_title: &str, blog_body: &str) -> Post {
use crate::schema::posts;
let new_post = NewPost { title:blog_title, body:blog_body };
diesel::insert_into(posts::table)
.values(&new_post)
.returning(Post::as_returning())
.get_result(connection)
.expect("Error saving new post")
}
//更新发布状态
pub fn db_update_post(connection: &mut PgConnection, post_id: i32) {
let post = diesel::update(posts.find(post_id))
.set(published.eq(true))
.returning(Post::as_returning())
.get_result(connection).optional();
match post {
Ok(Some(result)) => { println!("Published post {}", result.title); }
Ok(None) => { println!("unable fo find post {}", post_id) }
Err(error) => { println!("db_update_post:{}", error) }
}
}
// 查询指定id的数据
pub fn db_get_post(connection: &mut PgConnection, post_id: i32) {
let post = posts
.find(post_id)
.select(Post::as_select())
.first(connection)
.optional(); // This allows for returning an Option<Post>, otherwise it will throw an error
match post {
Ok(Some(post)) => println!("Post with id: {} has a title: {}", post.id, post.title),
Ok(None) => println!("Unable to find post {}", post_id),
Err(_) => println!("An error occured while fetching post {}", post_id),
}
}
// 查询发布状态的数据
pub fn db_show_posts(connection: &mut PgConnection, limit: i64) -> Vec<Post> {
let results = posts
.filter(published.eq(true))
.limit(limit)
.select(Post::as_select())
.load::<Post>(connection)
.expect("Error loading posts");
println!("Displaying {} posts", results.len());
for post in &results {
println!("id:{}", post.id);
println!("title:{}", post.title);
println!("------body-----\n");
println!("{}", post.body);
}
results
}
// 查询最多10000条数据，并作为数组返回
pub fn db_show_all_posts(connection: &mut PgConnection) -> Vec<Post> {
let results = posts
.limit(10000)
.select(Post::as_select())
.load::<Post>(connection)
.expect("Error loading posts");
println!("Displaying {} posts", results.len());
for post in &results {
println!("id:{}", post.id);
println!("title:{}", post.title);
println!("------body-----\n");
println!("{}", post.body);
}
results
}
//删除标题中含有某个字符串的数据
pub fn db_delete_post(connection: &mut PgConnection, pattern: &str) {
let num_deleted = diesel::delete(posts.filter(title.like(pattern)))
.execute(connection)
.expect("Error deleting posts");
println!("Deleted {} posts", num_deleted);
}
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