sqlite: affected rows count (#16426)

vlib/sqlite/sqlite.v

@@ -122,6 +122,8 @@ fn C.sqlite3_errmsg(&C.sqlite3) &char
 
 fn C.sqlite3_free(voidptr)
 
+fn C.sqlite3_changes(&C.sqlite3) int
+
 // connect Opens the connection with a database.
 pub fn connect(path string) !DB {
 	db := &C.sqlite3(0)
@@ -166,12 +168,17 @@ fn get_int_from_stmt(stmt &C.sqlite3_stmt) int {
 	return res
 }
 
-// Returns last insert rowid
+// last_insert_rowid returns last inserted rowid
 // https://www.sqlite.org/c3ref/last_insert_rowid.html
 pub fn (db &DB) last_insert_rowid() i64 {
 	return C.sqlite3_last_insert_rowid(db.conn)
 }
 
+// get_affected_rows_count returns `sqlite changes()` meaning amount of rows affected by most recent sql query
+pub fn (db &DB) get_affected_rows_count() int {
+	return C.sqlite3_changes(db.conn)
+}
+
 // Returns a single cell with value int.
 pub fn (db &DB) q_int(query string) int {
 	stmt := &C.sqlite3_stmt(0)

vlib/sqlite/sqlite_orm_test.v

@@ -22,6 +22,11 @@ struct TestDefaultAtribute {
 	created_at2 string [default: 'CURRENT_TIMESTAMP']
 }
 
+struct EntityToTest {
+	id   int    [notnull; sql_type: 'INTEGER']
+	smth string [notnull; sql_type: 'TEXT']
+}
+
 fn test_sqlite_orm() {
 	mut db := sqlite.connect(':memory:') or { panic(err) }
 	defer {
@@ -161,3 +166,64 @@ fn test_sqlite_orm() {
 		drop table TestDefaultAtribute
 	}
 }
+
+fn test_get_affected_rows_count() {
+	mut db := sqlite.connect(':memory:') or { panic(err) }
+	defer {
+		db.close() or { panic(err) }
+	}
+
+	db.exec('create table EntityToTest(
+		id integer not null constraint tbl_pk primary key,
+		smth  integer
+	);')
+
+	fst := EntityToTest{
+		id: 1
+		smth: '1'
+	}
+
+	sql db {
+		insert fst into EntityToTest
+	} or { panic('first insert failed') }
+
+	assert db.get_affected_rows_count() == 1
+
+	snd := EntityToTest{
+		id: 1
+		smth: '2'
+	}
+
+	mut sndfailed := false
+	sql db {
+		insert snd into EntityToTest
+	} or { sndfailed = true }
+
+	assert db.get_affected_rows_count() == 0
+	assert sndfailed
+
+	all := sql db {
+		select from EntityToTest
+	}
+	assert 1 == all.len
+
+	sql db {
+		update EntityToTest set smth = '2' where id == 1
+	}
+	assert db.get_affected_rows_count() == 1
+
+	sql db {
+		update EntityToTest set smth = '2' where id == 2
+	}
+	assert db.get_affected_rows_count() == 0
+
+	sql db {
+		delete from EntityToTest where id == 2
+	}
+	assert db.get_affected_rows_count() == 0
+
+	sql db {
+		delete from EntityToTest where id == 1
+	}
+	assert db.get_affected_rows_count() == 1
+}

vlib/sqlite/sqlite_test.v

@@ -10,6 +10,7 @@ fn test_sqlite() {
 	db.exec("create table users (id integer primary key, name text default '');")
 	db.exec("insert into users (name) values ('Sam')")
 	assert db.last_insert_rowid() == 1
+	assert db.get_affected_rows_count() == 1
 	db.exec("insert into users (name) values ('Peter')")
 	assert db.last_insert_rowid() == 2
 	db.exec("insert into users (name) values ('Kate')")
@@ -18,6 +19,11 @@ fn test_sqlite() {
 	assert nr_users == 3
 	name := db.q_string('select name from users where id = 1')
 	assert name == 'Sam'
+
+	// this insert will be rejected due to duplicated id
+	db.exec("insert into users (id,name) values (1,'Sam')")
+	assert db.get_affected_rows_count() == 0
+
 	users, mut code := db.exec('select * from users')
 	assert users.len == 3
 	assert code == 101
@@ -26,6 +32,19 @@ fn test_sqlite() {
 	user := db.exec_one('select * from users where id = 3') or { panic(err) }
 	println(user)
 	assert user.vals.len == 2
+
+	db.exec("update users set name='zzzz' where name='qqqq'")
+	assert db.get_affected_rows_count() == 0
+
+	db.exec("update users set name='Peter1' where name='Peter'")
+	assert db.get_affected_rows_count() == 1
+
+	db.exec("delete from users where name='qqqq'")
+	assert db.get_affected_rows_count() == 0
+
+	db.exec("delete from users where name='Sam'")
+	assert db.get_affected_rows_count() == 1
+
 	db.close() or { panic(err) }
 	assert !db.is_open
 }