写入数据int类型验证失败

反复检查了，写入数据库是报错“chunk-vendors.js:44497 Uncaught (in promise) Error: 数据库验证失败：["GrossWeight"]类型无效”，写入代码如下：
//将object 写数据库
export function writeObjectToDatabase(collectionName, objectToWrite) {
return new Promise((resolve, reject) => {
const db = uniCloud.database();
const collection = db.collection(collectionName);
collection.add(objectToWrite)
.then(result => {
resolve(result);
})
.catch(error => {
reject(error);
});
});
}