diesel_dynamic_schema/
column.rs

Help
1use diesel::backend::Backend;
2use diesel::expression::{is_aggregate, TypedExpressionType, ValidGrouping};
3use diesel::prelude::*;
4use diesel::query_builder::*;
5use std::borrow::Borrow;
6use std::marker::PhantomData;
7
8#[derive(Debug, Clone, Copy, Hash, PartialEq, Eq)]
9/// A database table column.
10/// This type is created by the [`column`](crate::Table::column()) function.
11pub struct Column<T, U, ST> {
12    table: T,
13    name: U,
14    _sql_type: PhantomData<ST>,
15}
16
17impl<T, U, ST> Column<T, U, ST> {
18    pub(crate) fn new(table: T, name: U) -> Self {
19        Self {
20            table,
21            name,
22            _sql_type: PhantomData,
23        }
24    }
25
26    /// Gets a reference to the table of the column.
27    pub fn table(&self) -> &T {
28        &self.table
29    }
30
31    /// Gets the name of the column, as provided on creation.
32    pub fn name(&self) -> &U {
33        &self.name
34    }
35}
36
37impl<T, U, ST> QueryId for Column<T, U, ST> {
38    type QueryId = ();
39    const HAS_STATIC_QUERY_ID: bool = false;
40}
41
42impl<T, U, ST, QS> SelectableExpression<QS> for Column<T, U, ST> where Self: Expression {}
43
44impl<T, U, ST, QS> AppearsOnTable<QS> for Column<T, U, ST> where Self: Expression {}
45
46impl<T, U, ST> Expression for Column<T, U, ST>
47where
48    ST: TypedExpressionType,
49{
50    type SqlType = ST;
51}
52
53impl<T, U, ST> ValidGrouping<()> for Column<T, U, ST> {
54    type IsAggregate = is_aggregate::No;
55}
56
57impl<T, U, ST, DB> QueryFragment<DB> for Column<T, U, ST>
58where
59    DB: Backend,
60    T: QueryFragment<DB>,
61    U: Borrow<str>,
62{
63    fn walk_ast<'b>(&'b self, mut out: AstPass<'_, 'b, DB>) -> QueryResult<()> {
64        out.unsafe_to_cache_prepared();
65        self.table.walk_ast(out.reborrow())?;
66        out.push_sql(".");
67        out.push_identifier(self.name.borrow())?;
68        Ok(())
69    }
70}
diesel_dynamic_schema/column.rs

diesel_dynamic_schema/
column.rs
