where condition with null in mysql

[hongxingshi]

ali-rds/test/operator.test.js

Line 18 in e4aed30

 assert.equal(op._where({ id: 1, name2: null }), ' WHERE `id` = 1 AND `name2` = NULL'); 

should be:

 assert.equal(op._where({ id: 1, name2: null }), ' WHERE `id` = 1 AND `name2` IS NULL');