[−][src]Trait actyxos_data_flow::db::DbRecord

pub trait DbRecord<D: DbMechanics>: Sized {
    fn table_version() -> i32;

    fn table_name() -> &'static str;

    fn columns() -> &'static [DbColumn];

    fn values(&self) -> Vec<D::SqlValue>;
}

representation of a database table for some record type

Required methods

fn table_version() -> i32

version number for the format

It is good practice to start with 1 and increment whenver the contents of the table should be recomputed (e.g. a logic change or a change to the column definitions).

fn table_name() -> &'static str

name of the table

If the database has been configured to use a common table_prefix() then that is prepended to this name to obtain the final name used in the database.

fn table_name() -> &'static str {
    "my_table"
}

fn columns() -> &'static [DbColumn]

columns of this table

Note that this intentionally has a return type that cannot be implemented dynamically.

fn columns() -> &'static [DbColumn] {
    static X: &[DbColumn] = &[
        DbColumn { name: "x", tpe: "bigint not null", exclude: false, index: true }
    ];
    X
}

fn values(&self) -> Vec<D::SqlValue>

values to fill the non-exluded columns as defined by the columns function

use actyxos_data_flow::db::{DbColumn, DbMechanics, DbRecord, SqliteDbMechanics};

struct X { x: i64 }

impl DbRecord<SqliteDbMechanics> for X {
    fn table_version() -> i32 { 1 }
    fn table_name() -> &'static str { "my_table" }
    fn columns() -> &'static [DbColumn] {
        static X: &[DbColumn] = &[
            DbColumn { name: "x", tpe: "bigint not null", exclude: false, index: true }
        ];
        X
    }
    fn values(&self) -> Vec<<SqliteDbMechanics as DbMechanics>::SqlValue> {
        vec![Box::new(self.x)]
    }
}

It is important to ensure that the values returned are fully consistent with all non-excluded column descriptions returned by the columns method, they must appear in the same order.

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Implementations on Foreign Types

impl<D: DbMechanics> DbRecord<D> for ()[src]

needed for the Union default type parameters — unused tables don’t have names and contain nothing

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Implementors

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