Postgres中不等于null

Question

如何!=在PostgreSQL SQL查询中过滤SQL结果？例

SELECT * FROM "A" WHERE "B" != 'C'

工作.但它也过滤了所有记录"B" IS NULL.当我将查询更改为:

SELECT * FROM "A" WHERE "B" != 'C' OR "B" IS NULL

我的结果是对的.O_O.总是,当我需要使用时!=我还需要检查OR "field" IS NULL？真？

在Sequelize中感到不舒服:{ B: { $or: [null, { $not: 'C' }] } }相反{ B: { $not: 'C' } }:(

Answer 1

您可以使用"null safe"运算符is distinct from代替<>

SELECT * 
FROM "A" 
WHERE "B" is distinct from 'C'

^{您还应该避免使用带引号的标识符.他们是值得的,他们更麻烦}