1
我需要從CSV文件(大約20K行)將數據導入到我的數據庫。有些行可能已經存在於數據庫中,因此只需要更新它們,但必須插入新行。如果任何操作失敗,交易必須取消。如何在書架上批量「插入」?
我該怎麼做?這是我使用的代碼:
var vehicle = {
id: row.id,
lastUpdate: moment(row.lastUpdate, 'DD/MM/YYYY - HH:mm').toDate(),
version: row.version,
color: row.color,
location: row.location,
status: row.status
};
Vehicle.forge({
id: row.id
})
.save(vehicle, { transacting: t, patch: true })
.then(model => {
console.log('*************' + vehicle.id);
})
.catch(Vehicle.NoRowsUpdatedError, err => {
// There are no rows for this chassis, so let's insert it
Vehicle.forge(vehicle)
.save(null, { transacting: t, method: 'insert' })
.then(model => {
console.log('++++++++++++++' + vehicle.id);
})
.catch(err => {
console.log(`INSERT ERROR: ${err.message}`);
t.rollback();
return res.json({ status: false, count: 0, error: err.message });
});
})
.catch(err => {
console.log(`UPDATE ERROR: ${err.message}`);
t.rollback();
return res.json({ status: false, count: 0, error: err.message });
});
此代碼是在for循環中,但在第二次迭代失敗可能是因爲promises
之間的併發。
我也嘗試添加一個自定義函數到我的模型文件,但它說該函數不存在。
let bookshelf = require('./base');
var Vehicle,
Vehicles;
Vehicle = bookshelf.Model.extend({
tableName: 'vehicles',
/**
* Insert a model based on data
* @param {Object} data
* @param {Object} [options] Options for model.save
* @return {Promise(bookshelf.Model)}
*/
create: function (data, options) {
return this.forge(data).save(null, options);
},
/**
* Select a model based on a query
* @param {Object} [query]
* @param {Object} [options] Options for model.fetch
* @param {Boolean} [options.require=false]
* @return {Promise(bookshelf.Model)}
*/
findOne: function (query, options) {
options = extend({ require: true }, options);
return this.forge(query).fetch(options);
},
/**
* Select a model based on data and update if found, insert if not found
* @param {Object} selectData Data for select
* @param {Object} updateData Data for update
* @param {Object} [options] Options for model.save
*/
upsert: function (selectData, updateData, options) {
return this.findOne(selectData, extend(options, { require: false }))
.bind(this)
.then(function (model) {
return model
? model.save(
updateData,
extend({ patch: true, method: 'update' }, options)
)
: this.create(
extend(selectData, updateData),
extend(options, { method: 'insert' })
)
});
}
});
Vehicles = bookshelf.Collection.extend({
model: Vehicle
});
module.exports = {
Vehicle: bookshelf.model('Vehicle', Vehicle),
Vehicles: bookshelf.collection('Vehicles', Vehicles)
};
這很好,除了在處理先前的查詢(驅動程序必須緩衝它們導致額外的內存消耗)之前,應該使用Bluebird.mapSeries來同時防止對DB驅動程序的併發查詢溢出。其他的事情是,不應該使用knex'toString()'來呈現串聯查詢,否則會導致很多類型的問題,例如。在插入的數據中帶有'?'標記。正確的方法是使用綁定並將查詢作爲參數傳遞,比如'trx.raw('?ON CONFLICT(id)DO UPDATE?',[insertQuery,setQuery])'以保持值綁定正確發送到db驅動程序。 –