can not parse "SET TIME ZONE 'UTC'"

[435201823]

It was normal to parse "SET TIME ZONE 'UTC'" a few days ago. Today I tried to parse "SET TIME ZONE 'UTC'" and there was an error.

pub fn sql_parse_test() {
    use sqlparser::dialect::GenericDialect;
    use sqlparser::parser::Parser;

    let sql = r#"set time zone 'UTC'"#;

    let dialect = GenericDialect {};

    let ast = Parser::parse_sql(&dialect, sql).unwrap();

    println!("AST: {:?}", ast);
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_sql_parse() {
        sql_parse_test();
    }
}

called `Result::unwrap()` on an `Err` value: ParserError("Expected equals sign or TO, found: zone")
thread 'func::sql_parse_test::tests::test_sql_parse' panicked at 'called `Result::unwrap()` on an `Err` value: ParserError("Expected equals sign or TO, found: zone")', src\func\sql_parse_test.rs:9:48

[waitingkuo]

@435201823 which sqlparser version did you use that worked? i switched back to 0.5.0 but it still not works

[step-baby]

The latest version of sqlparse still fails to parse SET TIME ZONE 'UTC'

[waitingkuo]

@alamb i think we could reopen this and discuss.
We only support SET TIME ZONE TO 'UTC' and SET TIME ZONE = 'UTC'
but not SET TIME ZONE 'UTC'

i'm not familiar with how other db works, in postgrseql, TIMEZONE is the only variable that support SET SOMETHING 'VALUE'
https://www.postgresql.org/docs/current/sql-set.html

[alamb]

Reopened -- I think the typical strategy in these cases is to reflect the difference between SET TIME ZONE = 'UTC'
and SET TIME ZONE 'UTC' in the ast and then downstream systems can figure out if they want to treat them equivalently or not

[waitingkuo]

@alamb i updated the pr