[UNFINISHED DRAFT] Implement HandleInsert and HandleBatchInsert for diesel::mysql::Mysql

Author: Alexei Pastuchov

wundergraph/src/query_builder/mutations/insert/mod.rs

@@ -15,6 +15,9 @@ mod pg;
 #[cfg(feature = "sqlite")]
 mod sqlite;
 
+#[cfg(feature = "mysql")]
+mod mysql;
+
 #[doc(hidden)]
 pub fn handle_insert<DB, I, R, Ctx>(
     selection: Option<&'_ [Selection<'_, WundergraphScalarValue>]>,

wundergraph/src/query_builder/mutations/insert/mysql.rs

@@ -0,0 +1,120 @@
+use super::{HandleBatchInsert, HandleInsert};
+use crate::context::WundergraphContext;
+use crate::helper::UnRef;
+use crate::query_builder::selection::fields::WundergraphFieldList;
+use crate::query_builder::selection::filter::build_filter::BuildFilter;
+use crate::query_builder::selection::order::BuildOrder;
+use crate::query_builder::selection::query_modifier::QueryModifier;
+use crate::query_builder::selection::select::BuildSelect;
+use crate::query_builder::selection::{LoadingHandler, SqlTypeOfPlaceholder};
+use crate::scalar::WundergraphScalarValue;
+use diesel::associations::HasTable;
+use diesel::dsl::SqlTypeOf;
+use diesel::expression::{Expression, NonAggregate, SelectableExpression};
+use diesel::insertable::CanInsertInSingleQuery;
+use diesel::mysql::Mysql;
+use diesel::query_builder::{BoxedSelectStatement, QueryFragment};
+use diesel::query_dsl::methods::{BoxedDsl, FilterDsl, LimitDsl};
+use diesel::sql_types::{Bigint, HasSqlType};
+use diesel::{AppearsOnTable, Connection, Insertable, RunQueryDsl, Table};
+use diesel::{no_arg_sql_function, EqAll, Identifiable, Queryable};
+use juniper::{ExecutionResult, Executor, Selection, Value};
+
+// https://dev.mysql.com/doc/refman/8.0/en/getting-unique-id.html
+diesel::no_arg_sql_function!(LAST_INSERT_ID, Bigint);
+
+impl<I, Ctx, L, T> HandleInsert<L, I, Mysql, Ctx> for T
+where
+    T: Table + HasTable<Table = T> + 'static,
+    T::FromClause: QueryFragment<Mysql>,
+    L: LoadingHandler<Mysql, Ctx, Table = T> + 'static,
+    L::Columns: BuildOrder<T, Mysql>
+        + BuildSelect<T, Mysql, SqlTypeOfPlaceholder<L::FieldList, Mysql, L::PrimaryKeyIndex, T, Ctx>>,
+    Ctx: WundergraphContext + QueryModifier<L, Mysql>,
+    Ctx::Connection: Connection<Backend = Mysql>,
+    L::FieldList: WundergraphFieldList<Mysql, L::PrimaryKeyIndex, T, Ctx>,
+    I: Insertable<T>,
+    I::Values: QueryFragment<Mysql> + CanInsertInSingleQuery<Mysql>,
+    T::PrimaryKey: QueryFragment<Mysql> + Default,
+    T: BoxedDsl<
+        'static,
+        Mysql,
+        Output = BoxedSelectStatement<'static, SqlTypeOf<<T as Table>::AllColumns>, T, Mysql>,
+    >,
+    <Ctx::Connection as Connection>::Backend: HasSqlType<SqlTypeOf<T::PrimaryKey>>
+        + HasSqlType<SqlTypeOfPlaceholder<L::FieldList, Mysql, L::PrimaryKeyIndex, T, Ctx>>,
+    <L::Filter as BuildFilter<Mysql>>::Ret: AppearsOnTable<T>,
+    T::PrimaryKey: EqAll<i32>,
+    T::PrimaryKey: Expression<SqlType = diesel::sql_types::Integer>,
+    &'static L: Identifiable,
+    <&'static L as Identifiable>::Id: UnRef<'static, UnRefed = i32>,
+    <T::PrimaryKey as EqAll<i32>>::Output:
+        SelectableExpression<T> + NonAggregate + QueryFragment<Mysql> + 'static,
+{
+    fn handle_insert(
+        selection: Option<&'_ [Selection<'_, WundergraphScalarValue>]>,
+        executor: &Executor<'_, Ctx, WundergraphScalarValue>,
+        insertable: I,
+    ) -> ExecutionResult<WundergraphScalarValue> {
+        let ctx = executor.context();
+        let conn = ctx.get_connection();
+        conn.transaction(|| -> ExecutionResult<WundergraphScalarValue> {
+            let look_ahead = executor.look_ahead();
+            insertable.insert_into(T::table()).execute(conn)?;
+
+            let last_insert_id: i64 =  diesel::select(LAST_INSERT_ID).first(conn)?;
+
+            let q = L::build_query(&[], &look_ahead)?;
+            let q = FilterDsl::filter(q, T::PrimaryKey::default().eq_all(last_insert_id as i32));
+            let q = LimitDsl::limit(q, 1);
+            #[cfg(feature = "debug")]
+            {
+                log::debug!("{}", ::diesel::debug_query(&q));
+            }
+            let items = L::load(&look_ahead, selection, executor, q)?;
+
+            Ok(items.into_iter().next().unwrap_or(Value::Null))
+        })
+    }
+}
+
+impl<I, Ctx, L, T, Id> HandleBatchInsert<L, I, Mysql, Ctx> for T
+where
+    T: Table + HasTable<Table = T> + 'static,
+    T::FromClause: QueryFragment<Mysql>,
+    L: LoadingHandler<Mysql, Ctx, Table = T> + 'static,
+    L::Columns: BuildOrder<T, Mysql>
+        + BuildSelect<T, Mysql, SqlTypeOfPlaceholder<L::FieldList, Mysql, L::PrimaryKeyIndex, T, Ctx>>,
+    Ctx: WundergraphContext + QueryModifier<L, Mysql>,
+    Ctx::Connection: Connection<Backend = Mysql>,
+    L::FieldList: WundergraphFieldList<Mysql, L::PrimaryKeyIndex, T, Ctx>,
+    Vec<I>: Insertable<T>,
+    <Vec<I> as Insertable<T>>::Values: QueryFragment<Mysql> + CanInsertInSingleQuery<Mysql>,
+    T::PrimaryKey: QueryFragment<Mysql> + Default,
+    T: BoxedDsl<
+        'static,
+        Mysql,
+        Output = BoxedSelectStatement<'static, SqlTypeOf<<T as Table>::AllColumns>, T, Mysql>,
+    >,
+    <Ctx::Connection as Connection>::Backend: HasSqlType<SqlTypeOf<T::PrimaryKey>>
+        + HasSqlType<SqlTypeOfPlaceholder<L::FieldList, Mysql, L::PrimaryKeyIndex, T, Ctx>>,
+    <L::Filter as BuildFilter<Mysql>>::Ret: AppearsOnTable<T>,
+    T::PrimaryKey: EqAll<Id>,
+    &'static L: Identifiable,
+    <&'static L as Identifiable>::Id: UnRef<'static, UnRefed = Id>,
+    Id: Queryable<<T::PrimaryKey as Expression>::SqlType, Mysql>,
+    <T::PrimaryKey as EqAll<Id>>::Output:
+        SelectableExpression<T> + NonAggregate + QueryFragment<Mysql> + 'static,
+{
+    fn handle_batch_insert(
+        _selection: Option<&'_ [Selection<'_, WundergraphScalarValue>]>,
+        executor: &Executor<'_, Ctx, WundergraphScalarValue>,
+        _batch: Vec<I>,
+    ) -> ExecutionResult<WundergraphScalarValue> {
+        let ctx = executor.context();
+        let conn = ctx.get_connection();
+        conn.transaction(|| -> ExecutionResult<WundergraphScalarValue> {
+            unimplemented!()
+        })
+    }
+}