jsonb 数组项选择的 where 子句不起作用

Question

我试试这个

SELECT elem
FROM jsonb_array_elements('["*", "12/05/2020"]'::jsonb) AS elem
WHERE elem::text != '*';

还有这个

SELECT * FROM (
SELECT elem::text 
FROM jsonb_array_elements('["*", "12/05/2020"]'::jsonb) AS elem
) elems WHERE elem != '*'

还有

SELECT * FROM (
SELECT elem::text 
FROM jsonb_array_elements('["*", "12/05/2020"]'::jsonb) AS elem
) elems WHERE elem::text != '*'

并期待所有情况下的结果

"12/05/2020"

。但是得到

"*", "12/05/2020"

。

为什么？

Answer 1

事实上我已经找到答案了：

SELECT elem
FROM jsonb_array_elements('["*", "12/05/2020"]'::jsonb) AS elem
WHERE elem::text != '"*"';

您需要单引号和双引号！