Casting columns as a different data type on select, insert and update

[billy1624]

PR Info

• Related Support citext seaography#104

New Features

• Added ColumnTrait::select_as() and ColumnTrait::select_enum_as() methods: casting select expression of a column
• Added ColumnTrait::save_as() and ColumnTrait::save_enum_as() methods: casting value of a column in insert and update statement
• Added select_as and save_as macro attribute to DeriveEntityModel

[karatakis]

Looks fine by me

[tyt2y3]

What I don't understand is, under what circumstance is not default?
How do I customize the behaviour?
This seems to be part of the public API, and is it intended? Can we hide it instead?

[billy1624]

It's intended to be part of the public API. For example, user can override it and cast citext column type as text during select, SELECT CAST("citext_column" AS text), ....

[billy1624]

I'll add a self-explanatory test case now

[billy1624]

Added 6295fcf

[tyt2y3]

Ah okay, the only remaining question now is naming.

For example cast_value_enum only do any casting only if it is an enum and so I think it will be better named as may_be_cast_value_enum

But then, cast_value is also a bit confusing. I understand now it's the counterpart to cast_select, but of course cast_insert_or_update is too long as a name. So may be we can use the word, save.

And so, the entire naming could be: select_as and save_as, cast_save_as etc?

[billy1624]

I think select_as and save_as are short and concise. How about?

• select_as: casting columns on select
• select_enum_as: casting enum columns on select
• save_as: casting columns on insert and update
• save_enum_as: casting enum columns on insert and update

[tyt2y3]

sounds good!

[billy1624]

Nice! I'll work on that :)

[praveenperera]

@billy1624 Hey this does not seem to work, I tried the sea-orm on master:

sea-orm = {git = "https://github.com/SeaQL/sea-orm", features = ["runtime-tokio-native-tls", "sqlx-postgres", "macros"]}

Tried inserting:

    let user_params = UserActiveModel::from_json(user_json)?.set_timestamps();
    let user = user_params.insert(&state.database_connection).await?;

Entity:

//! `SeaORM` Entity. Generated by sea-orm-codegen 0.10.7
use sea_orm::{entity::prelude::*, Set};
use serde::{Deserialize, Serialize};

#[derive(Clone, Debug, PartialEq, DeriveEntityModel, Eq, Serialize, Deserialize)]
#[sea_orm(table_name = "users")]
pub struct Model {
    #[sea_orm(primary_key, auto_increment = false)]
    #[serde(skip_deserializing)] // Skip deserializing
    pub id: Uuid,
    pub first_name: String,
    pub last_name: String,
    #[sea_orm(unique)]
    pub nickname: String,
    pub password: String,
    #[sea_orm(
        column_type = r#"Custom("citext".into())"#,
        save_as = "citext"
        select_as = "text",
    )]
    pub email: String,
    pub country: String,
    #[serde(skip_deserializing)]
    pub created_at: DateTimeUtc,
    #[serde(skip_deserializing)]
    pub updated_at: DateTimeUtc,
}

#[derive(Copy, Clone, Debug, EnumIter, DeriveRelation)]
pub enum Relation {}

impl ActiveModelBehavior for ActiveModel {}

impl ActiveModel {
    pub fn set_timestamps(mut self) -> Self {
        if self.created_at.is_not_set() {
            self.created_at = Set(chrono::Utc::now())
        }
        self.updated_at = Set(chrono::Utc::now());
        self
    }
}

Error

Query Error: error occurred while decoding column \"email\": mismatched types; Rust type `core::option::Option<alloc::string::String>` (as SQL type `TEXT`) is not compatible with SQL type `citext

[billy1624]

Hey @praveenperera, thanks for asking!! Notice the select_as is text.

    #[sea_orm(
        column_type = r#"Custom("citext".into())"#,
        save_as = "citext"
-       select_as = "citext",
+       select_as = "text",
    )]
    pub email: String,

[praveenperera]

Hey @billy1624, sorry that's what I had before and I was changing stuff to try stuff out. I tried select_as ="text" again and same error. I invited you to the repo to check it out. On the citext branch: https://github.com/praveenperera/rest-template-rust/tree/citext

[billy1624]

Okay. I know what have happened... "a missing ," I was surprised that Rust compiler didn't thrown any errors loll

    #[sea_orm(
        column_type = r#"Custom("citext".into())"#,
-       save_as = "citext"
+       save_as = "citext",
        select_as = "text",
    )]
    pub email: String,

[praveenperera]

Hmm interesting that actually fixed it. Thanks!

[billy1624]

Nice!

[praveenperera]

@billy1624 Would this be possible to use when using the --expanded-format?

Got it, maybe would be a good thing to add to docs?

impl ColumnTrait for Column {
    type EntityName = Entity;
    fn def(&self) -> ColumnDef {
        match self {
            Self::Id => ColumnType::Uuid.def(),
            Self::FirstName => ColumnType::String(Some(255u32)).def(),
            Self::LastName => ColumnType::String(Some(255u32)).def(),
            Self::Nickname => ColumnType::String(Some(255u32)).def().unique(),
            Self::HashedPassword => ColumnType::String(Some(255u32)).def(),
            Self::Email => ColumnType::Custom("citext".to_owned()).def().unique(),
            Self::Country => ColumnType::String(Some(255u32)).def(),
            Self::CreatedAt => ColumnType::TimestampWithTimeZone.def(),
            Self::UpdatedAt => ColumnType::TimestampWithTimeZone.def(),
        }
    }

    fn select_as(&self, expr: Expr) -> SimpleExpr {
        match self {
            Self::Email => SimpleExpr::cast_as(Into::<SimpleExpr>::into(expr), Alias::new("text")),
            _ => self.select_enum_as(expr),
        }
    }
}