tilde ~ in where condition

[krishna krishna]

Hi Team,

I am need your help to understand why tilde expression is used in the SQL query in where condition

we have below table

Slno resources joining_date_time
1 josheph 2022-12-11 00:00:00:00
2 william 2021-07-11 00:00:00:00


below is the query created in SQL , So would like to understand

select resources where joining_date_time = ~joining~

however Joining itself is not there inthe joining_date_time column.

please assist