A safe, extensible ORM and Query Builder for Rust – For feature requests and longer questions also see https://github.com/diesel-rs/diesel/discussions/categories/q-a
the trait bound `query_builder::sql_query::UncheckedBind<SqlQuery, u32, diesel::sql_types::Unsigned<diesel::sql_types::Integer>>: LoadQuery<_, Exhibitions>` is not satisfied
the following implementations were found:
<query_builder::sql_query::UncheckedBind<Query, Value, ST> as LoadQuery<Conn, T>>#[derive(QueryableByName)]
struct Exhibitions {
#[sql_type = "String"]
exhibitions: String,
}
#[post("/sqlconnect/readExhibitions.php", data = "<form>")]
pub fn get_handler(
form: Form<GetHandlerForm>,
conn: Database,
) -> Result<JsonValue, Custom<String>> {
Ok(
match sql_query(include_str!("select_exhibitions.sql"))
.bind::<Unsigned<Integer>, _>(form.cid)
.load::<Exhibitions>(&*conn)
.map_err(|e| Custom(Status::InternalServerError, e.to_string()))?
.pop()
.map(|w| w.exhibitions)
{
Some(json) => serde_json::to_value(json)
.map_err(|e| {
Custom(
Status::InternalServerError,
format!("Failed to serialize Exhibitions: {}", e.to_string()),
)
})?
.into(),
None => json!({
"exhibitions": []
}),
},
)
}load. Since Exhibitions derives from QueryableByName, I thought I could load it from the query, but something is wrong.
exhibitions member of the struct refers to the exhibitions column in the table returned by my custom query. And that's a big JSON_OBJECT.
Is it possible to conditionally perform update on conflicts with multiple values? (I'm using postrgres)
Something like this:
#[derive(Insertable)]
struct InsertPost {
id: i64,
date: NaiveDate,
}
let insert_vec = vec![Test{id: 1, date: "2014.05.05"}, Test{id: 2, date: "2013.03.05"}];
diesel::insert_into(tests)
.values(&insert_vec)
.on_conflict(id)
.do_update()
.filter(date.ge(excluded(date)))
.set(date.eq(excluded(date)));I want to insert multiple values and only update the rows that meet a certain criteria, is there any way to acheive this?
The example above does not compile as the type IncompleteDoUpdate type does not contain a filter method.
Hello folks,
I'm trying to do a simple sum in a Postgres BIGINT (NOT NULL) column:
orders.select(sum(units))
.filter(user_id.eq(&p_user_id))
.first(&connection).unwrap()(Where orders is the table, units is the BIGINT column and user_id is just a filter.)
When I try to assign it to an i64 variable it throws:
60 | .first(&connection).unwrap();
| ^^^^^ the trait `diesel::deserialize::FromSql<diesel::sql_types::Nullable<diesel::sql_types::Numeric>, diesel::pg::Pg>` is not implemented for `i64`
|
= help: the following implementations were found:
<i64 as diesel::deserialize::FromSql<diesel::sql_types::BigInt, DB>>When I try to assign to a BigInt variable it throws:
.first(&connection).unwrap();
| ^^^^^ the trait `diesel::Queryable<diesel::sql_types::Nullable<diesel::sql_types::Numeric>, diesel::pg::Pg>` is not implemented for `diesel::sql_types::BigInt`
|
= note: required because of the requirements on the impl of `diesel::query_dsl::LoadQuery<diesel::PgConnection, diesel::sql_types::BigInt>`Similar errors happen when I try to wrap the type using an Option (Option<i64> or Option<BigInt> var).
Could you please help me to identify what's wrong here?
Hi, I have a question about many to many realtions. I have the follwing tables
CREATE TABLE articles
(
id SERIAL NOT NULL UNIQUE PRIMARY KEY,
urn_title VARCHAR(50) NOT NULL UNIQUE,
title VARCHAR(50) NOT NULL UNIQUE,
tags TEXT[] NOT NULL,
description VARCHAR(200) NOT NULL,
authors TEXT[] NOT NULL,
edit_count INTEGER NOT NULL DEFAULT 0,
last_edited TIMESTAMP DEFAULT current_timestamp NOT NULL,
status BOOLEAN NOT NULL DEFAULT true,
publicized BOOLEAN NOT NULL DEFAULT false,
featured BOOLEAN NOT NULL DEFAULT false
);
CREATE TABLE users
(
id TEXT NOT NULL PRIMARY KEY,
username TEXT NOT NULL,
discriminator TEXT NOT NULL,
avatar TEXT NOT NULL,
rank INTEGER NOT NULL DEFAULT 1,
contributed_articles INT[]
);
CREATE TABLE user_articles
(
author_id TEXT REFERENCES users,
article_id INT REFERENCES articles,
PRIMARY KEY (article_id, author_id)
);The following code returns an empty array
#[derive(Queryable, Associations, Identifiable)]
#[belongs_to(ArticleModel, foreign_key = "article_id")]
#[belongs_to(UserModel, foreign_key = "author_id")]
#[primary_key(article_id, author_id)]
pub struct UserArticle {
author_id: String,
article_id: i32,
}
impl UserArticle {
pub fn find_user_articles(user: &UserModel, conn: &PgConnection) -> Result<Vec<ArticleModel>, diesel::result::Error>{
UserArticle::belonging_to(user)
.inner_join(articles::table)
.select(ARTICLE_COLUMNS)
.load::<ArticleModel>(conn)
}
}I was wondering if I need to insert anything into user_articlesin order to be able to do many to many realtions. In this scenario, a user can have many articles and a articles can have many users (contributers). I have trired reading up on many to many and have read the stackoverflow question on many to many in diesel but I am still confused. Thank you for any help!
2 replies
1 reply
Bascially i am looking functionality like this (Actually in other ORM/query builder we can specify ? for value & ?? for column name/table name)
https://github.com/mysqljs/mysql#escaping-query-identifiers
Is there any way in diesel to do this or maybe some sort of escape method to avoid sql injection?
Hello 😀 I'm trying to do a diesel setup on my MacBook Pro M1 and I'm having this error:
dyld: lazy symbol binding failed: Symbol not found: _PQconnectdb
Referenced from: /Users/thibaultrobert/.cargo/bin/diesel
Expected in: flat namespace
dyld: Symbol not found: _PQconnectdb
Referenced from: /Users/thibaultrobert/.cargo/bin/diesel
Expected in: flat namespace
[1] 33071 abort diesel setupPostgresql is installed and it works I can access the DB with the psql command
If anyone has any clue 😀
Thanks in advance
Hi everyone! I'd like to add support for RETURNING in SQLite to the library, as per recent community discussions. To get things started, I made the relevant changes to the diesel code in a fork. However, this fails CI in a way I hadn't expected, apparently calling for another feature in SQLite:
error[E0277]: the trait bound `Sqlite: SupportsDefaultKeyword` is not satisfied
Error: --> diesel_tests/tests/insert.rs:76:10
|
76 | .get_results::<User>(&connection)
| ^^^^^^^^^^^ the trait `SupportsDefaultKeyword` is not implemented for `Sqlite`
|
= note: required because of the requirements on the impl of `diesel::query_builder::QueryFragment<Sqlite>` for `BatchInsert<'_, schema::NewUser, schema::users::table>`
= note: 1 redundant requirements hidden
= note: required because of the requirements on the impl of `diesel::query_builder::QueryFragment<Sqlite>` for `InsertStatement<schema::users::table, BatchInsert<'_, schema::NewUser, schema::users::table>, diesel::query_builder::insert_statement::Insert, diesel::query_builder::returning_clause::ReturningClause<(schema::users::columns::id, schema::users::columns::name, schema::users::columns::hair_color)>>`
= note: required because of the requirements on the impl of `LoadQuery<diesel::SqliteConnection, schema::User>` for `InsertStatement<schema::users::table, BatchInsert<'_, schema::NewUser, schema::users::table>>`I'm confused by this because the batch insert does work, using nearly identical code in related tests. This particular error has been reported and discussed a couple of times already in this channel, too, but the solutions that have previously been suggested (i.e. using the correct Connection type) don't seem to apply here. Can you see what's going on? Any hints or clues are massively appreciated (I'm learning Rust, so apologies in advance if this is something trivial -- I'm happy to read up on things if you could give me a starting point). Thanks!
4 replies
Option around the bool field.
Hi Everyone,
am struggling my way through a small problem that is mostly to do with my unfamiliarity with diesel traits and dynamic dispatch,
I have the below example table...
table! {
samples (id) {
id -> Integer,
name -> Text,
content -> Text,
version -> Integer,
created -> Timestamp,
}
}and I am trying to design a dynamic filter object for it for a graphQL app to take as an input on filtering and returning sample records
#[derive(juniper::GraphQLInputObject)]
pub struct Filter{
pub comparitor: Comparitor,
pub column: Columns,
pub value: String // probably will need to be better typed but its a placeholder for now,
}I have a drafted up enum for a limited set of query types
#[derive(juniper::GraphQLEnum)]
pub enum Comparitor {
Eq, // equal to
Gt, // greater than
Lt, // less than
Ge, // greater than equal to
Le, // less than equal to
Li, // like
Ne, // not equal to
Ng, // not greater than
Nl, // not less than
Nge, // not greater than equal to
Nle, // not less than equal to
Nl, // not like
}and an enum of columns
#[derive(juniper::GraphQLEnum)]
enum Columns {
id,
name,
content,
version,
created,
}which is fine (maybe still have to get to its implementation) until I want to coerce from an input value to a table column with something a bit like the below
impl Columns {
fn as_table(self) { //type sig purposely left off since that's kind of the trouble
match self {
Columns::id => samlples::columns::id,
Columns::name => samlples::columns::name,
Columns::content => samlples::columns::content,
Columns::version => samlples::columns::version,
Columns::created => samlples::columns::created,
}
}
}I don't honestly know enough about either the guts of diesel or rust's generics or dynamic dispatch so I am kinda blindly following the compilers screams on this and sadly the compiler was unable to be any more helpful in guessing what I actually am trying to do.
Any help or hints would be greatly appreciated.
2 replies
diesel::sql_types::SingleValue is not implemented for (diesel::sql_types::Integer, diesel::sql_types::Text, diesel::sql_types::Integer)
3 replies