postgresql Postgres 中的不等于和空

Question

提问by faiwer

How I can filter SQL results with !=in PostgreSQL SQL query? Example

如何!=在 PostgreSQL SQL 查询中过滤 SQL 结果？例子

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

Working. But it's also filtered all record where "B" IS NULL. When I changed query to:

在职的。但它也过滤了所有记录 where "B" IS NULL。当我将查询更改为：

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

I'm got right result. O_o. Always, when I need using !=I need also check OR "field" IS NULL? Really?

我得到了正确的结果。哦哦。总是，当我需要使用时，!=我还需要检查OR "field" IS NULL? 真的吗？

It's uncomfortable in Sequelize: { B: { $or: [null, { $not: 'C' }] } }, instead: { B: { $not: 'C' } }:(

在 Sequelize 中很不舒服：{ B: { $or: [null, { $not: 'C' }] } }，而是：{ B: { $not: 'C' } }:(

Answer 1

You can use the "null safe" operator is distinct frominstead of <>

您可以使用“空安全”运算符is distinct from而不是<>

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

^{You should also avoid quoted identifiers. They are much more trouble then they are worth it}

^{您还应该避免引用标识符。他们的麻烦比他们值得}