Function json_eq 

pub fn json_eq<'a, L, R>(left: L, field: &'a str, value: R) -> SQLiteSQL<'a>
where
    L: ToSQL<'a, SQLiteValue<'a>>,
    R: Into<SQLiteValue<'a>> + ToSQL<'a, SQLiteValue<'a>>,

Create a JSON field equality condition using SQLite ->> operator

Example

let column = SQL::<SQLiteValue>::raw("metadata");
let condition = json_eq(column, "theme", "dark");
assert_eq!(condition.sql(), "metadata ->>'theme' = ?");