loopback 04

数据库相关

关系定义

relations: {
"images": {
"type": "hasMany",
"model": "image",
"polymorphic": "imageable"
}
}

//
Item.create(itemData).then((item)=> {
item.image.create().then(){
}
})

继承默认User表

username,password

//一般表的结构
{
"name": "other",
"base": "PersistedModel",
....
}

//继承User表的结构
{
"name": "user",
"base": "User",
...
}

修改数据类型为指定数据库类型

"details": {
"type": [
"object"
],
"postgresql": {
"dataType": "text"
}
}

使用mixins

server/model-config.js

{
...
"mixins": [
"loopback/common/mixins",
"loopback/server/mixins",
"../common/mixins",
"./mixins"
]
...
}

common/models/*.json

{
...
"mixins": {"Timestamp": {"myOption": 1}},
...
}

common/mixins/timestamp.js

module.exports = function(Model, options) {
// Model is the model class
// options is an object containing the config properties from model definition
Model.defineProperty('created', {type: Date, default: '$now'});
Model.defineProperty('modified', {type: Date, default: '$now'});
}

使用正则表达式

Item.find({
where: {
or: [
{
a: {regexp: ...},      //{like: '%%'}
b: {regexp: ...}
}
]
}
}).then(items=> callback(null, items)).catch(callback);

测试辅助

app.datasources.pg.autoupdate([
'user',.....
]);

describe('Item Model definition', ()=> {
let db = app.datasources.pg;
let item = db.getModelDefinition('item');

it('has the following properties', ()=> {
expect(item.properties.content.type).to.eql(String);
expect(item.properties.thumbsup.type).to.eql(Number);
expect(item.properties.userId.type).to.eql(Number);
.....
});
});

beforeEach(done=> {
app.dataSources.pg.automigrate(['item','tag','image'], ()=> {
Item.create(itemData).then((item)=> {
itemOne = item;
itemId = item.id;
done();
})
})
});
.....
});

继承loopback自定义的数据库

{
"name": "user",
"base": "User",
...
}

debug运行

DEBUG=* npm start

数据库关系

BelongsTo

hasMany,hasOne

HasMany

belongsTo

HasOne

belongsTo

HasManyThrough

belongsTo

keyThrough

HasAndBelongsToMany

id

HasManyThrough

hasAndBelongsToMany

Polymorphic relations

loopback常用命令

slc loopback:model

slc loopback:acl

常用数据库操作

创建

PersistedModel.create(data, callback)

PersistedModel.upsert(data, callback)

PersistedModel.findOrCreate([where], data, callback)

persistedModel.save([options], callback)

更新

PersistedModel.updateAll([where], data, callback)

persistedModel.updateAttribute(name, value, callback)

persistedModel.updateAttributes(data, callback)

PersistedModel.createUpdates(deltas, callback)

PersistedModel.bulkUpdate(updates, callback)

销毁

PersistedModel.destroyAll([where], callback)

PersistedModel.destroyById(id, callback)

debug检查

DEBUG=loopback:connector:postgresql npm start

使用

loopback

自带的数据验证;

validation

使用

loopback-console

直接操作数据;

关于hook

before|afterRemote()

observe()

loopback.getModel('xxx')

添加方法

Item.search = function(filter, keyword, callback) {
filter = filter || {};
let query = {regexp: `/${keyword}/i`};

delete filter.where;

if (keyword) {
filter.where = {
or: [
{content: query, deleted: false, visible: true},
{tagString: query, deleted: false, visible: true}
]
};
}

Item.find(filter).then(items=> callback(null, items)).catch(callback);
};

Activity.prototype.increaseViews = function(nums, callback) {
callback(null, {views: this.views});
};

Activity.beforeRemote('prototype.increaseViews', (ctx, instance, next)=> {
const nums = ctx.req.query.nums || 1;
instance && instance.updateAttribute('views', instance.views + Number(nums))
.then(()=> next()).catch(next);
});

Item.remoteMethod('search', {
description: '',
accepts: [
{ arg: 'filter', type: 'object', http: {source: 'query|object'} },
],
http: {verb: 'get|post|put...'},
returns: { root: true, type: '' }
});

去掉

explore

root/explore.js

components.config

数据筛选

{ fields: {id: true, make: true, model: true} }

id

include

id

include