use crate::backend::{sql_dialect, Backend};
use crate::expression::{AppearsOnTable, Expression};
use crate::query_builder::*;
use crate::query_source::*;
use crate::result::QueryResult;
#[doc(hidden)]
#[derive(Debug, Clone, Copy, QueryId)]
pub struct DoNothing;
impl<DB> QueryFragment<DB> for DoNothing
where
DB: Backend,
Self: QueryFragment<DB, DB::OnConflictClause>,
{
fn walk_ast<'b>(&'b self, pass: AstPass<'_, 'b, DB>) -> QueryResult<()> {
<Self as QueryFragment<DB, DB::OnConflictClause>>::walk_ast(self, pass)
}
}
impl<DB, T> QueryFragment<DB, T> for DoNothing
where
DB: Backend,
T: sql_dialect::on_conflict_clause::SupportsOnConflictClause,
{
fn walk_ast<'b>(&'b self, mut out: AstPass<'_, 'b, DB>) -> QueryResult<()> {
out.push_sql(" DO NOTHING");
Ok(())
}
}
#[doc(hidden)]
#[derive(Debug, Clone, Copy, QueryId)]
pub struct DoUpdate<T> {
changeset: T,
}
impl<T> DoUpdate<T> {
pub(crate) fn new(changeset: T) -> Self {
DoUpdate { changeset }
}
}
impl<DB, T> QueryFragment<DB> for DoUpdate<T>
where
DB: Backend,
Self: QueryFragment<DB, DB::OnConflictClause>,
{
fn walk_ast<'b>(&'b self, pass: AstPass<'_, 'b, DB>) -> QueryResult<()> {
<Self as QueryFragment<DB, DB::OnConflictClause>>::walk_ast(self, pass)
}
}
impl<DB, T, SP> QueryFragment<DB, SP> for DoUpdate<T>
where
DB: Backend,
SP: sql_dialect::on_conflict_clause::SupportsOnConflictClause,
T: QueryFragment<DB>,
{
fn walk_ast<'b>(&'b self, mut out: AstPass<'_, 'b, DB>) -> QueryResult<()> {
out.unsafe_to_cache_prepared();
if self.changeset.is_noop(out.backend())? {
out.push_sql(" DO NOTHING");
} else {
out.push_sql(" DO UPDATE SET ");
self.changeset.walk_ast(out.reborrow())?;
}
Ok(())
}
}
#[doc(hidden)]
#[derive(Debug, Clone, Copy, QueryId)]
pub struct Excluded<T>(T);
impl<T> Excluded<T> {
pub(crate) fn new(t: T) -> Self {
Excluded(t)
}
}
impl<DB, T> QueryFragment<DB> for Excluded<T>
where
DB: Backend,
Self: QueryFragment<DB, DB::OnConflictClause>,
{
fn walk_ast<'b>(&'b self, pass: AstPass<'_, 'b, DB>) -> QueryResult<()> {
<Self as QueryFragment<DB, DB::OnConflictClause>>::walk_ast(self, pass)
}
}
impl<DB, T, SP> QueryFragment<DB, SP> for Excluded<T>
where
DB: Backend,
SP: sql_dialect::on_conflict_clause::SupportsOnConflictClause,
T: Column,
{
fn walk_ast<'b>(&'b self, mut out: AstPass<'_, 'b, DB>) -> QueryResult<()> {
out.push_sql("excluded.");
out.push_identifier(T::NAME)?;
Ok(())
}
}
impl<T> Expression for Excluded<T>
where
T: Expression,
{
type SqlType = T::SqlType;
}
impl<T> AppearsOnTable<T::Table> for Excluded<T>
where
T: Column,
Excluded<T>: Expression,
{
}