在使用NodeJS来关系型操作数据库时，为了方便，通常都会选择一个合适的ORM（Object Relationship Model）框架。毕竟直接操作SQL比较繁琐，通过ORM框架，我们可以使用面向对象的方式来操作表。NodeJS社区有很多的ORM框架，我比较喜欢Sequelize，它功能丰富，可以非常方便的进行连表查询,事务处理等。

今天简单介绍下 sequelize 操作符：

sequelize:

var users = yield User.findAll({
    'where': {
        'id': {
            '$eq': 1,                // id = 1
            '$ne': 2,                // id != 2

            '$gt': 6,                // id > 6
            '$gte': 6,               // id >= 6

            '$lt': 10,               // id < 10
            '$lte': 10,              // id <= 10

            '$between': [6, 10],     // id BETWEEN 6 AND 10
            '$notBetween': [11, 15], // id NOT BETWEEN 11 AND 15

            '$in': [1, 2],           // id IN (1, 2)
            '$notIn': [3, 4]         // id NOT IN (3, 4)
        },
        'nick': {
            '$like': '%a%',          // nick LIKE '%a%'
            '$notLike': '%a'         // nick NOT LIKE '%a'
        },
        'updated_at': {
            '$eq': null,             // updated_at IS NULL
            '$ne': null              // created_at IS NOT NULL
        }
    }
});

sql：

SELECT `id`, `emp_id`, `nick`, `department`, `created_at`, `updated_at` 
FROM `users` AS `user` 
WHERE 
(
    `user`.`id` = 1 AND 
    `user`.`id` != 2 AND 
    `user`.`id` > 6 AND 
    `user`.`id` >= 6 AND 
    `user`.`id` < 10 AND 
    `user`.`id` <= 10 AND 
    `user`.`id` BETWEEN 6 AND 10 AND 
    `user`.`id` NOT BETWEEN 11 AND 15 AND
    `user`.`id` IN (1, 2) AND 
    `user`.`id` NOT IN (3, 4)
) 
AND 
(
    `user`.`nick` LIKE '%a%' AND 
    `user`.`nick` NOT LIKE '%a'
) 
AND 
(
    `user`.`updated_at` IS NULL AND 
    `user`.`updated_at` IS NOT NULL
);