MySQL 向 GraphQL 迁移-36大数据

GraphQL 是一个开源的图形数据库(基于Node.js实现), 中文文档:  https://graphql.js.cool/

sequelize-auto 将 MySQL 数据库转变成模型

				
				[node] sequelize-auto -h <host> -d <database> -u <user> -x [password] -p [port] --dialect [dialect] -c [/path/to/config] -o [/path/to/models] -t [tableName] -C 参数: -h, --host 主机地址 [必须] -d, --database 数据名 [必须] -u, --user 用户名 -x, --pass 密码 -p, --port 端口号 -c, --config 配置文件,参考: https://sequelize.readthedocs.org/en/latest/api/sequelize/ -o, --output 输出目录 -e, --dialect 数据库引擎: postgres, mysql, sqlite -t, --tables 需要导入的表 -T, --skip-tables 需要排除的表 -C, --camel 使用用驼峰命名法 -n, --no-write 不需要写入文件 -s, --schema 数据库结构
			

使用数据模型

这里是生成的一个示例模型:

				/* jshint indent: 2 */
				module.exports = function(sequelize, DataTypes) {
				return sequelize.define('d_user', {
				uid: {
				type: DataTypes.INTEGER(11).UNSIGNED,
				allowNull: false,
				primaryKey: true
				},
				username: {
				type: DataTypes.STRING(16),
				allowNull: false,
				defaultValue: ''
				},
				mobile: {
				type: DataTypes.STRING(16),
				allowNull: false,
				defaultValue: ''
				},
				email: {
				type: DataTypes.STRING(32),
				allowNull: false,
				defaultValue: ''
				},
				password: {
				type: DataTypes.STRING(32),
				allowNull: false,
				defaultValue: ''
				},
				salt: {
				type: DataTypes.STRING(8),
				allowNull: false,
				defaultValue: ''
				},
				updatedAt: {
				type: DataTypes.INTEGER(10).UNSIGNED,
				allowNull: false
				}
				}, {
				tableName: 'user'
				});
				};
			

创建数据库模型:

				
				const Sequelize = require('sequelize'); const Db = new Sequelize('数据库名', '用户名', '密码', { host: 'localhost', dialect: 'mysql' }) const User = Db.define('user', { uid: { type: Sequelize.INTEGER(11).UNSIGNED, allowNull: false, primaryKey: true }, username: { type: Sequelize.STRING(16), allowNull: false, defaultValue: '' }, mobile: { type: Sequelize.STRING(16), allowNull: false, defaultValue: '' }, email: { type: Sequelize.STRING(32), allowNull: false, defaultValue: '' }, password: { type: Sequelize.STRING(32), allowNull: false, defaultValue: '' }, salt: { type: Sequelize.STRING(8), allowNull: false, defaultValue: '' } }, { tableName: 'user',
				// 取消默认的时间戳, 否则会报 createdAt 不存在错误
				timestamps: false }); Db.sync(); module.exports = { Db, User };
			

graphql-sequelize 转换 MySQL -> GraphQL 结构

				const { GraphQLObjectType,GraphQLSchema,GraphQLList,GraphQLInt,GraphQLString } = require('graphql');
				const { attributeFields, resolver } = require('graphql-sequelize');
				const { Db, User } = require('./db');
				userType = new GraphQLObjectType({
				name: 'User',
				description: 'A user',
				fields: attributeFields(User)
				});
				const Query = new GraphQLObjectType({
				name: 'Query',
				description: 'Root query object',
				fields: () => {
				return {
				user: {
				type: new GraphQLList(userType),
				args: {
				uid: {
				type: GraphQLInt
				},
				email: {
				type: GraphQLString
				}
				},
				resolve(root, args) {
				return Db.models.user.findAll({ where: args });
				}
				}
				};
				}
				});
				const Schema = new GraphQLSchema({
				query: Query
				});
				module.exports = Schema;
			

启动服务器

				const Express =require( 'express');
				const GraphHTTP =require( 'express-graphql');
				const Schema =require( './schema');
				// Config
				const APP_PORT = 3000;
				// Start
				const app = Express();
				// GraphQL
				app.use('/graphql', GraphHTTP({
				schema: Schema,
				pretty: true,
				graphiql: true
				}));
				app.listen(APP_PORT, ()=> {
				console.log(`App listening on port ${APP_PORT}`);
			

End.

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