orm: fix fkey insert as assigment expr (fix #25568) (#25575)

Author: kbkpbot

vlib/orm/orm_fk_test.v

@@ -52,7 +52,54 @@ fn test_field_after_fkeys() {
 	persons := sql db {
 		select from Person
 	}!
-
 	assert persons[0].age == 21
 	assert persons[0].field_after_fkeys == 'eee'
 }
+
+@[table: 'foos']
+struct Foo {
+	id       int @[primary; sql: serial]
+	name     string
+	children []Child @[fkey: 'parent_id']
+}
+
+struct Child {
+	id        int @[primary; sql: serial]
+	parent_id int
+	name      string
+}
+
+fn test_fkey_insert_as_assignment_expr() {
+	db := sqlite.connect(':memory:')!
+
+	sql db {
+		create table Foo
+		create table Child
+	}!
+
+	foo := Foo{
+		name:     'abc'
+		children: [
+			Child{
+				name: 'abc'
+			},
+			Child{
+				name: 'def'
+			},
+		]
+	}
+	// use insert as an assigment expr
+	_ := sql db {
+		insert foo into Foo
+	}!
+
+	result := sql db {
+		select from Foo where id == 1
+	}!
+	assert result[0].children.len == 2
+
+	res := sql db {
+		select from Child
+	}!
+	assert res.len == 2
+}

vlib/v/checker/orm.v

@@ -71,6 +71,7 @@ fn (mut c Checker) sql_expr(mut node ast.SqlExpr) ast.Type {
 		foreign_typ := c.get_field_foreign_table_type(field)
 
 		mut subquery_expr := ast.SqlExpr{
+			inserted_var: field.name
 			pos:          node.pos
 			has_where:    true
 			where_expr:   ast.None{}

vlib/v/gen/c/orm.v

@@ -53,18 +53,26 @@ fn (mut g Gen) sql_insert_expr(node ast.SqlExpr) {
 	g.sql_table_name = g.table.sym(node.table_expr.typ).name
 
 	// orm_insert needs an SqlStmtLine, build it from SqlExpr (most nodes are the same)
-	hack_stmt_line := ast.SqlStmtLine{
-		object_var: node.inserted_var
-		fields:     node.fields
-		table_expr: node.table_expr
-		// sub_structs: node.sub_structs
-	}
+	hack_stmt_line := g.build_sql_stmt_line_from_sql_expr(node)
 	g.write_orm_insert(hack_stmt_line, table_name, connection_var_name, result_var_name,
 		node.or_expr, table_attrs)
 
 	g.write2(left, 'orm__Connection_name_table[${connection_var_name}._typ]._method_last_id(${connection_var_name}._object)')
 }
 
+fn (mut g Gen) build_sql_stmt_line_from_sql_expr(node ast.SqlExpr) ast.SqlStmtLine {
+	mut sub_structs := map[int]ast.SqlStmtLine{}
+	for typ, sub in node.sub_structs {
+		sub_structs[typ] = g.build_sql_stmt_line_from_sql_expr(sub)
+	}
+	return ast.SqlStmtLine{
+		object_var:  node.inserted_var
+		fields:      node.fields
+		table_expr:  node.table_expr
+		sub_structs: sub_structs
+	}
+}
+
 // sql_stmt writes C code that calls ORM functions for
 // performing various database operations such as creating and dropping tables,
 // as well as inserting and updating objects.