database-introspection: Fix on delete actions for MySQL

server/prisma-rs/libs/database-introspection/src/mysql.rs

@@ -185,6 +185,17 @@ impl IntrospectionConnector {
                 .get("ordinal_position")
                 .and_then(|x| x.as_i64())
                 .expect("get ordinal_position");
+            let on_delete_action = match row
+                .get("delete_rule")
+                .and_then(|x| x.to_string())
+                .expect("get delete_rule").to_lowercase().as_str() {
+                    "cascade" => ForeignKeyAction::Cascade,
+                    "set null" => ForeignKeyAction::SetNull,
+                    "set default" => ForeignKeyAction::SetDefault,
+                    "restrict" => ForeignKeyAction::Restrict,
+                    "no action" => ForeignKeyAction::NoAction,
+                    s @ _ => panic!(format!("Unrecognized on delete action '{}'", s)),
+                };
             match intermediate_fks.get_mut(&constraint_name) {
                 Some(fk) => {
                     let pos = ord_pos as usize - 1;
@@ -202,7 +213,7 @@ impl IntrospectionConnector {
                         columns: vec![column],
                         referenced_table,
                         referenced_columns: vec![referenced_column],
-                        on_delete_action: ForeignKeyAction::NoAction,
+                        on_delete_action,
                     };
                     intermediate_fks.insert(constraint_name, fk);
                 }

server/prisma-rs/libs/database-introspection/tests/introspection_connection_tests.rs

@@ -1516,6 +1516,119 @@ fn postgres_foreign_key_on_delete_must_be_handled() {
     );
 }
 
+#[test]
+fn mysql_foreign_key_on_delete_must_be_handled() {
+    setup();
+
+    // NB: We don't test the SET DEFAULT variety since it isn't supported on InnoDB and will
+    // just cause an error
+    let sql = format!(
+        "CREATE TABLE {0}.City (id INTEGER NOT NULL AUTO_INCREMENT PRIMARY KEY);
+         CREATE TABLE {0}.User (
+            id INTEGER NOT NULL AUTO_INCREMENT PRIMARY KEY,
+            city INTEGER, FOREIGN KEY(city) REFERENCES City (id) ON DELETE NO ACTION,
+            city_cascade INTEGER, FOREIGN KEY(city_cascade) REFERENCES City (id) ON DELETE CASCADE,
+            city_restrict INTEGER, FOREIGN KEY(city_restrict) REFERENCES City (id) ON DELETE RESTRICT,
+            city_set_null INTEGER, FOREIGN KEY(city_set_null) REFERENCES City (id) ON DELETE SET NULL
+        )",
+        SCHEMA
+    );
+    let inspector = get_mysql_connector(&sql);
+
+    let schema = inspector.introspect(SCHEMA).expect("introspection");
+    let mut table = schema.get_table("User").expect("get User table").to_owned();
+    table.foreign_keys.sort_unstable_by_key(|fk| fk.columns.clone());
+
+    assert_eq!(
+        table,
+        Table {
+            name: "User".to_string(),
+            columns: vec![
+                Column {
+                    name: "city".to_string(),
+                    tpe: ColumnType {
+                        raw: "int".to_string(),
+                        family: ColumnTypeFamily::Int,
+                    },
+                    arity: ColumnArity::Nullable,
+                    default: None,
+                    auto_increment: false,
+                },
+                Column {
+                    name: "city_cascade".to_string(),
+                    tpe: ColumnType {
+                        raw: "int".to_string(),
+                        family: ColumnTypeFamily::Int,
+                    },
+                    arity: ColumnArity::Nullable,
+                    default: None,
+                    auto_increment: false,
+                },
+                Column {
+                    name: "city_restrict".to_string(),
+                    tpe: ColumnType {
+                        raw: "int".to_string(),
+                        family: ColumnTypeFamily::Int,
+                    },
+                    arity: ColumnArity::Nullable,
+                    default: None,
+                    auto_increment: false,
+                },
+                Column {
+                    name: "city_set_null".to_string(),
+                    tpe: ColumnType {
+                        raw: "int".to_string(),
+                        family: ColumnTypeFamily::Int,
+                    },
+                    arity: ColumnArity::Nullable,
+                    default: None,
+                    auto_increment: false,
+                },
+                Column {
+                    name: "id".to_string(),
+                    tpe: ColumnType {
+                        raw: "int".to_string(),
+                        family: ColumnTypeFamily::Int,
+                    },
+                    arity: ColumnArity::Required,
+                    default: None,
+                    auto_increment: true,
+                },
+            ],
+            indices: vec![],
+            primary_key: Some(PrimaryKey {
+                columns: vec!["id".to_string()],
+            }),
+            foreign_keys: vec![
+                ForeignKey {
+                    columns: vec!["city".to_string()],
+                    referenced_columns: vec!["id".to_string()],
+                    referenced_table: "City".to_string(),
+                    on_delete_action: ForeignKeyAction::NoAction,
+                },
+                ForeignKey {
+                    columns: vec!["city_cascade".to_string()],
+                    referenced_columns: vec!["id".to_string()],
+                    referenced_table: "City".to_string(),
+                    on_delete_action: ForeignKeyAction::Cascade,
+                },
+                ForeignKey {
+                    columns: vec!["city_restrict".to_string()],
+                    referenced_columns: vec!["id".to_string()],
+                    referenced_table: "City".to_string(),
+                    on_delete_action: ForeignKeyAction::Restrict,
+                },
+                ForeignKey {
+                    columns: vec!["city_set_null".to_string()],
+                    referenced_columns: vec!["id".to_string()],
+                    referenced_table: "City".to_string(),
+                    on_delete_action: ForeignKeyAction::SetNull,
+                },
+            ],
+        }
+    );
+}
+
 #[test]
 fn postgres_enums_must_work() {
     setup();