为什么Sequelize发布“SHOW INDEX FROM`table`”？(Why Sequelize issues “SHOW INDEX FROM `table`”?)

 如果要启用Sequelize日志记录，您会看到在“同步”阶段和创建表之后， Sequelize执行SHOW INDEX FROM table查询。 问题是 - 为什么？ 
 
 
 更具体地说，这是我正在执行的代码： 
 
var Sequelize = require('sequelize');

var connection = new Sequelize('demo_schema', 'root', 'password');

var Article = connection.define('article', {
    slug: {
        type: Sequelize.STRING,
        primaryKey: true
    },
    title: {
        type: Sequelize.STRING,
        unique: true,
        allowNull: false
    },
    body:  {
        type: Sequelize.TEXT
    }
}, {
    timestamps: false
});

connection.sync({
    force: true,
    logging: console.log
}).then(function () {
   // TODO
});
 
 这是控制台上的输出： 
 
Executing (default): DROP TABLE IF EXISTS `articles`;
Executing (default): DROP TABLE IF EXISTS `articles`;
Executing (default): CREATE TABLE IF NOT EXISTS `articles` (`slug` VARCHAR(255) , `title` VARCHAR(255) NOT NULL UNIQUE, `body` TEXT, UNIQUE `articles_title_unique` (`title`), PRIMARY KEY (`slug`)) ENGINE=InnoDB;
Executing (default): SHOW INDEX FROM `articles`

If you would enable Sequelize logging, you would see that during the "sync" phase and right after creating a table, Sequelize executes SHOW INDEX FROM table query. The question is - why?
 
 
To be more specific, here is the code I'm executing:
 
var Sequelize = require('sequelize');

var connection = new Sequelize('demo_schema', 'root', 'password');

var Article = connection.define('article', {
    slug: {
        type: Sequelize.STRING,
        primaryKey: true
    },
    title: {
        type: Sequelize.STRING,
        unique: true,
        allowNull: false
    },
    body:  {
        type: Sequelize.TEXT
    }
}, {
    timestamps: false
});

connection.sync({
    force: true,
    logging: console.log
}).then(function () {
   // TODO
});
 
Here is the output on the console:
 
Executing (default): DROP TABLE IF EXISTS `articles`;
Executing (default): DROP TABLE IF EXISTS `articles`;
Executing (default): CREATE TABLE IF NOT EXISTS `articles` (`slug` VARCHAR(255) , `title` VARCHAR(255) NOT NULL UNIQUE, `body` TEXT, UNIQUE `articles_title_unique` (`title`), PRIMARY KEY (`slug`)) ENGINE=InnoDB;
Executing (default): SHOW INDEX FROM `articles`

原文：https://stackoverflow.com/questions/37893128