sql - Postgres和Rust R2D2 : How to get array_to_json as text/string without the escaped double quotes?

Question

我有以下SQL:

select jsonb_agg(t) 
from ( 
 select username, notifications 
 from useraccountview where username = 'Bobby'
) t;

这在PSQL中为我提供了以下内容:

[{"username":"Bobby","notifications":0}]

当我放入 ::text时:

select jsonb_agg(t)::text 
from (
  select username, notifications 
  from useraccountview where username = 'Bobby'
) t;

我仍然得到相同的:

[{"username":"Bobby","notifications":0}]

但是在使用r2d2_postgres的rust应用程序方面，我得到了一个转义的字符串:

"[{\"username\":\"Bobby\",\"notifications\":0}]"

rust 代码:

let qr = conn.query("select jsonb_agg(t)::text from (select username, notifications from useraccount where username = $1) t",&[&param]).unwrap();
let value: &str = qr[0].get(0);
println!("{:?}",value);

输出:

"[{\"username\":\"Bobby\",\"notifications\":0}]"

如何防止双引号转义？

Answer 1

报价仅在打印过程中转义。它们不会在内存中逃脱。如果要打印不带引号的值，请使用println!("{}", value);。