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
Is there any plan to support batch insertion for Postgres using COPY IN STDIN? I think it is not possible with MySQL and SQLite.
I know that rust-postgres support it : https://github.com/sfackler/rust-postgres/blob/master/tokio-postgres/tests/test/main.rs#L479
Hi everyone, I am getting a weird error: the trait bound uuid::Uuid: diesel::Expression is not satisfied while #[derive(Insertable...)] on diesel 1.4.4 (with features="uuid") and uuid = "0.6.5" on a table definition with a simple table defined as #[derive(Insertable, Queryable, Identifiable, SimpleObject, Debug, Clone)]
[table_name = "user"]
[primary_key(id)]
pub struct User {
pub id: uuid::Uuid,
pub name: String,
pub age: i32,
}
is there something I am missing?
1 reply
Hi guys, I've been pulling my hair out trying to figure out how to do what I imagine is a simple query filtering rows that were created this month. This sql is what i would like to replicate in correct diesel syntax:
select * from my_table where extract (month from postdate) = extract (month from CURRENT_DATE);
Im trying: my_table.filter(postdate.month().eq(Chrono::Utc::now().month()))
Error is that postdate which is type timestamptz has no method month(). Definitely would appreciate a any help. It's my first swing at building a web service so apologies in advance for any ignorance.
1 reply
Creating database: postgres://prwad:prwad@127.0.0.1:5432/prwad?sslmode=disablebut then does nothing with it.
Compiling diesel_cli v1.4.1
error: linking withccfailed: exit code: 1 (but I feel that isn't a diesel issue.)
I'm running a complicated, raw SQL query using sql_query. I'll post it as a reply to this thread.
It works when I'm running it locally. I'm running it in a Rocket unit test on Windows, connected to a local MySQL database.
When I deploy it on AWS Lambda, it gives me an SQL error: Using unsupported buffer type: 245 (parameter: 1)
When deployed, it connects to an AWS RDS MySQL database.
I'm not sure how to start troubleshooting this, since the query does run on both MySQL servers if I substitute the ? parameter with a literal. I would like some help understanding what could cause this difference, and also understanding what the error means.
The closest I could find was this: https://forums.mysql.com/read.php?168,242330,242330
But that's a different error, with no responses.
40 replies
use diesel::*;
use diesel::{
deserialize::{FromSql, Result as DResult},
pg::Pg,
serialize::{IsNull, Output, Result as SResult, ToSql},
};
use serde::{Deserialize, Serialize};
use std::io::Write;
#[derive(Debug, Clone, Serialize, Deserialize, AsExpression, PartialEq)]
#[diesel(not_sized)]
pub struct ShortTextElement {
pub name: String,
pub value: Option<String>,
}
#[derive(Debug, Clone, Serialize, Deserialize, AsExpression, PartialEq)]
#[diesel(not_sized)]
pub struct TextElement {
pub name: String,
}
#[derive(SqlType)]
#[postgres(type_name = "Jsonb")]
pub struct FormElement;
#[derive(Debug, PartialEq, Serialize, Deserialize, FromSqlRow, AsExpression)]
#[sql_type = "FormElement"]
#[diesel(not_sized)]
pub enum FormElementEnum {
ShortTextElement(ShortTextElement),
TextElement(TextElement),
}
/// Copied from diesel source for JSONB with slight variation with distinctive encoding
impl ToSql<FormElement, Pg> for FormElementEnum {
fn to_sql<W: Write>(&self, out: &mut Output<W, Pg>) -> SResult {
out.write_all(&[2])?;
serde_json::to_writer(out, self)
.map(|_| IsNull::No)
.map_err(Into::into)
}
}
/// Copied from diesel source for JSONB with slight variation with distinctive encoding
impl ToSql<FormElementEnum, Pg> for FormElementEnum {
fn to_sql<W: Write>(&self, out: &mut Output<W, Pg>) -> SResult {
out.write_all(&[2])?;
serde_json::to_writer(out, self)
.map(|_| IsNull::No)
.map_err(Into::into)
}
}
/// Copied from diesel source for JSONB with slight variation with distinctive encoding
impl FromSql<FormElement, Pg> for FormElementEnum {
fn from_sql(nullable: Option<&[u8]>) -> DResult<Self> {
let bytes = not_none!(nullable);
if bytes[0] != 2 {
return Err("Unsupported JSONB encoding version".into());
}
serde_json::from_slice(&bytes[1..]).map_err(|_| "Invalid Json".into())
}
}
/// Copied from diesel source for JSONB with slight variation with distinctive encoding
impl FromSql<FormElementEnum, Pg> for FormElementEnum {
fn from_sql(nullable: Option<&[u8]>) -> DResult<Self> {
let bytes = not_none!(nullable);
if bytes[0] != 2 {
return Err("Unsupported JSONB encoding version".into());
}
serde_json::from_slice(&bytes[1..]).map_err(|_| "Invalid Json".into())
}
}
3 replies
#[sql_type = "blub"] annotations for your #[derive(AsExperssion)] attributes.
serde_json::Value without parsing twice? My intention was to have an enum that can be used as a type in the models that already has a specific structure. So that I can guarantee all elements in the DB have this type and aren't 'just' Values?
FormElementEnum you only need to implement FromSql/ToSql for this type.
-- Your SQL goes here
CREATE UNIQUE INDEX tx_hash_index
ON sol_transaction(tx_hash);
CREATE TABLE order_transaction(
order_id VARCHAR(255) NOT NULL ,
tx_hash VARCHAR(255) UNIQUE NOT NULL,
PRIMARY KEY(order_id, tx_hash),
CONSTRAINT tx_hash_fk FOREIGN KEY(tx_hash)
REFERENCES sol_transaction(tx_hash)
ON DELETE CASCADE
);-- Your SQL goes here
CREATE TABLE sol_transaction(
id BIGSERIAL PRIMARY KEY,
tx_hash VARCHAR(255) NOT NULL,
from_address VARCHAR(255) NOT NULL,
to_address VARCHAR(255) NOT NULL,
VALUE DOUBLE PRECISION NOT NULL DEFAULT 0,
BLOCK_HASH VARCHAR(255) NOT NULL,
BLOCK_HEIGHT BIGINT NOT NULL,
BLOCK_TIME TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP
)tx_hash is NOT NULL in both files
1 reply
1 reply