参见：

文档地址

v7：
https://sequelize.org/v7/

v6:
https://sequelize.org/v6/index.html

V7

https://sequelize.org/v7/identifiers.html
没看见Sequelize的部分

V6

https://sequelize.org/v6/class/src/sequelize.js~Sequelize.html
Public Constructors部分

Public Constructors

public constructor(database: string, username: string, password: string, options: object)

用数据库名、用户名和密码实例化sequelize。

options

类型：Object
描述：可选的配置信息。它的具体属性都是可选的。并且有的提供了默认值。

看着sequelize的options对象，突然明白了配置对象为什么一般都叫options，而不叫configuration。
因为option本身就有选择的意思，意思是这个配置对象是可选的，并不需要开发者去填写。

host

类型：string
默认值：’localhost’
描述：关系数据库的主机地址

port

类型：number
默认值：无
描述：关系数据库的端口。

username

类型：string
默认值：null
描述：
关系数据库的主机地址

define

类型：object
默认值：{}
描述：定义模型的默认选项。详见Model.init。
Default options for model definitions. See Model.init.

options object
- optional
- default: {}
 An object with options.
options.host string
- optional
- default: ‘localhost’
 关系数据库的主机地址
options.port number
- optional
 The port of the relational database.
options.username string
- optional
- default: null
 The username which is used to authenticate against the database.
options.password string
- optional
- default: null
 The password which is used to authenticate against the database.
options.database string
- optional
- default: null
 The name of the database.
options.dialect string
- optional
 The dialect of the database you are connecting to. One of mysql, postgres, sqlite, db2, mariadb and mssql.
options.dialectModule string
- optional
- default: null
 If specified, use this dialect library. For example, if you want to use pg.js instead of pg when connecting to a pg database, you should specify ‘require(“pg.js”)’ here
options.dialectModulePath string
- optional
- default: null
 If specified, load the dialect library from this path. For example, if you want to use pg.js instead of pg when connecting to a pg database, you should specify ‘/path/to/pg.js’ here
options.dialectOptions object
- optional
 An object of additional options, which are passed directly to the connection library
options.storage string
- optional
 Only used by sqlite. Defaults to ‘:memory:’
options.protocol string
- optional
- default: ‘tcp’
 The protocol of the relational database.
options.define object
- optional
- default: {}
 定义模型的默认选项。详见 Model.init.
options.query object
- optional
- default: {}
 Default options for sequelize.query
options.schema string
- optional
- default: null
 A schema to use
options.set object
- optional
- default: {}
 Default options for sequelize.set
options.sync object
- optional
- default: {}
 Default options for sequelize.sync
options.timezone string
- optional
- default: ‘+00:00’
 The timezone used when converting a date from the database into a JavaScript date. The timezone is also used to SET TIMEZONE when connecting to the server, to ensure that the result of NOW, CURRENT_TIMESTAMP and other time related functions have in the right timezone. For best cross platform performance use the format +/-HH:MM. Will also accept string versions of timezones used by moment.js (e.g. ‘America/Los_Angeles’); this is useful to capture daylight savings time changes.
options.clientMinMessages string
| boolean
- optional
- default: ‘warning’
 (Deprecated) The PostgreSQL client_min_messages session parameter. Set to false to not override the database’s default.
options.standardConformingStrings boolean
- optional
- default: true
 The PostgreSQL standard_conforming_strings session parameter. Set to false to not set the option. WARNING: Setting this to false may expose vulnerabilities and is not recommended!
options.logging Function
- optional
- default: console.log
 A function that gets executed every time Sequelize would log something. Function may receive multiple parameters but only first one is printed by console.log. To print all values use (…msg) => console.log(msg)
options.benchmark boolean
- optional
- default: false
 Pass query execution time in milliseconds as second argument to logging function (options.logging).
options.omitNull boolean
- optional
- default: false
 A flag that defines if null values should be passed as values to CREATE/UPDATE SQL queries or not.
options.native boolean
- optional
- default: false
 A flag that defines if native library shall be used or not. Currently only has an effect for postgres
options.replication boolean
- optional
- default: false
 Use read / write replication. To enable replication, pass an object, with two properties, read and write. Write should be an object (a single server for handling writes), and read an array of object (several servers to handle reads). Each read/write server can have the following properties: host, port, username, password, database
options.pool object
- optional
 sequelize connection pool configuration
options.pool.max number
- optional
- default: 5
 Maximum number of connection in pool
options.pool.min number
- optional
- default: 0
 Minimum number of connection in pool
options.pool.idle number
- optional
- default: 10000
 The maximum time, in milliseconds, that a connection can be idle before being released.
options.pool.acquire number
- optional
- default: 60000
 The maximum time, in milliseconds, that pool will try to get connection before throwing error
options.pool.evict number
- optional
- default: 1000
 The time interval, in milliseconds, after which sequelize-pool will remove idle connections.
options.pool.validate Function
- optional
 A function that validates a connection. Called with client. The default function checks that client is an object, and that its state is not disconnected
options.pool.maxUses number
- optional
- default: Infinity
 The number of times a connection can be used before discarding it for a replacement, used for eventual cluster rebalancing.
options.quoteIdentifiers boolean
- optional
- default: true
 Set to false to make table names and attributes case-insensitive on Postgres and skip double quoting of them. WARNING: Setting this to false may expose vulnerabilities and is not recommended!
options.transactionType string
- optional
- default: ‘DEFERRED’
 Set the default transaction type. See Sequelize.Transaction.TYPES for possible options. Sqlite only.
options.isolationLevel string
- optional
 Set the default transaction isolation level. See Sequelize.Transaction.ISOLATION_LEVELS for possible options.
options.retry object
- optional
 Set of flags that control when a query is automatically retried. Accepts all options for retry-as-promised.
options.retry.match Array
- optional
 Only retry a query if the error matches one of these strings.
options.retry.max number
- optional
 How many times a failing query is automatically retried. Set to 0 to disable retrying on SQL_BUSY error.
options.typeValidation boolean
- optional
- default: false
 Run built-in type validators on insert and update, and select with where clause, e.g. validate that arguments passed to integer fields are integer-like.
options.operatorsAliases object
- optional
 String based operator alias. Pass object to limit set of aliased operators.
options.hooks object
- optional
 An object of global hook functions that are called before and after certain lifecycle events. Global hooks will run after any model-specific hooks defined for the same event (See Sequelize.Model.init() for a list). Additionally, beforeConnect(), afterConnect(), beforeDisconnect(), and afterDisconnect() hooks may be defined here.
options.minifyAliases boolean
- optional
- default: false
 A flag that defines if aliases should be minified (mostly useful to avoid Postgres alias character limit of 64)
options.logQueryParameters boolean
- optional
- default: false
 A flag that defines if show bind parameters in log.

logging

optional
type: Function
default: default: console.log
描述：

A function that gets executed every time Sequelize would log something. Function may receive multiple parameters but only first one is printed by console.log. To print all values use (…msg) => console.log(msg)

经验：
默认是console.log，可在控制台中打印原始的sql语句。
可设置为一个函数，使用它来代理默认的console.log操作。
可设置为false，表示不打印。

Model.init参数