From bf959a2534d23c5c667ea3914bc57d6ef2aeb2b2 Mon Sep 17 00:00:00 2001
From: Tobias Wiese <tobias@tobiaswiese.com>
Date: Wed, 3 Dec 2025 21:49:13 +0100
Subject: Initial commit

Signed-off-by: Tobias Wiese <tobias@tobiaswiese.com>
---
 src/db.rs | 149 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 149 insertions(+)
 create mode 100644 src/db.rs

(limited to 'src/db.rs')

diff --git a/src/db.rs b/src/db.rs
new file mode 100644
index 0000000..b088f0a
--- /dev/null
+++ b/src/db.rs
@@ -0,0 +1,149 @@
+#![allow(non_camel_case_types)]
+
+use diesel::backend::Backend;
+use diesel::expression::{
+    IsContainedInGroupBy, ValidGrouping, is_aggregate, is_contained_in_group_by,
+};
+use diesel::internal::table_macro::{FromClause, SelectStatement};
+use diesel::prelude::*;
+use diesel::query_builder::{AsQuery, AstPass, QueryFragment, QueryId};
+use diesel::query_source::{AppearsInFromClause, Once, Table as TableTrait};
+use diesel::sql_types::{Text, Uuid};
+
+pub use self::columns::*;
+
+pub mod columns {
+    use super::*;
+
+    macro_rules! col {
+        ($col:ident, $sql_type:ty) => {
+            pub struct $col;
+
+            impl Expression for $col {
+                type SqlType = $sql_type;
+            }
+
+            impl<'a, QS> AppearsOnTable<QS> for $col where
+                QS: AppearsInFromClause<super::Table<'a>, Count = Once>
+            {
+            }
+
+            impl<'a> SelectableExpression<super::Table<'a>> for $col {}
+
+            impl ValidGrouping<()> for $col {
+                type IsAggregate = is_aggregate::No;
+            }
+
+            impl<GB> ValidGrouping<GB> for $col
+            where
+                GB: IsContainedInGroupBy<$col, Output = is_contained_in_group_by::Yes>,
+            {
+                type IsAggregate = is_aggregate::Yes;
+            }
+
+            impl<'a> Column for $col {
+                type Table = Table<'static>;
+
+                const NAME: &'static str = stringify!($col);
+            }
+
+            impl<DB> QueryFragment<DB> for $col
+            where
+                DB: Backend,
+            {
+                fn walk_ast<'b>(&'b self, mut pass: AstPass<'_, 'b, DB>) -> QueryResult<()> {
+                    pass.push_identifier(<$col as Column>::NAME)?;
+                    Ok(())
+                }
+            }
+
+            impl QueryId for $col {
+                type QueryId = $col;
+
+                const HAS_STATIC_QUERY_ID: bool = true;
+            }
+        };
+    }
+
+    col!(id, Uuid);
+    col!(username, Text);
+    col!(token, Text);
+}
+
+//pub const all_columns: <Table<'static> as TableTrait>::AllColumns = (id, username, token);
+
+pub type SqlType = (Uuid, Text, Text);
+
+#[derive(Debug, Clone, Copy, Hash, PartialEq, Eq)]
+pub struct Table<'a> {
+    name: &'a str,
+    schema: Option<&'a str>,
+}
+
+impl<'a> Table<'a> {
+    pub fn new(name: &'a str, schema: Option<&'a str>) -> Self {
+        Self { name, schema }
+    }
+}
+
+impl QuerySource for Table<'_> {
+    type FromClause = Self;
+    type DefaultSelection = <Self as TableTrait>::AllColumns;
+
+    fn from_clause(&self) -> Self::FromClause {
+        self.clone()
+    }
+
+    fn default_selection(&self) -> Self::DefaultSelection {
+        <Self as TableTrait>::all_columns()
+    }
+}
+
+impl AsQuery for Table<'_> {
+    type SqlType = SqlType;
+    type Query = SelectStatement<FromClause<Self>>;
+
+    fn as_query(self) -> Self::Query {
+        SelectStatement::simple(self)
+    }
+}
+
+impl TableTrait for Table<'_>
+where
+    Self: QuerySource + AsQuery,
+{
+    type PrimaryKey = id;
+    type AllColumns = (id, username, token);
+
+    fn primary_key(&self) -> Self::PrimaryKey {
+        id
+    }
+
+    fn all_columns() -> Self::AllColumns {
+        (id, username, token)
+    }
+}
+
+impl<DB> QueryFragment<DB> for Table<'_>
+where
+    DB: Backend,
+{
+    fn walk_ast<'b>(&'b self, mut pass: AstPass<'_, 'b, DB>) -> QueryResult<()> {
+        if let Some(ref schema) = self.schema {
+            pass.push_identifier(schema)?;
+            pass.push_sql(".");
+        }
+        pass.push_identifier(self.name)?;
+        Ok(())
+    }
+}
+
+impl QueryId for Table<'_> {
+    type QueryId = ();
+
+    const HAS_STATIC_QUERY_ID: bool = false;
+}
+
+impl AppearsInFromClause<Table<'_>> for Table<'_> {
+    type Count = Once;
+}
-- 
cgit v1.2.3