/// Format expr to SQL string.
Format expr to SQL string.
Format expr to SQL string .
pub fn expr_sql_string(&self) -> String {
        let mut out = String::new();
        for expr in &self.exprs {
            if !out.is_empty() {
                write!(&mut out, " AND ").expect("writing to a string shouldn't fail");
            }
            write!(&mut out, "{}", expr).expect("writing to a string shouldn't fail");
        }
        out
    }
pub fn expr_sql_string ( & self ) -> String { let mut out = String :: new ( ) ; for expr in & self . exprs { if ! out . is_empty ( ) { write ! ( mut out " " ) . expect ( " " ) ; } write ! ( mut out " " expr ) . expect ( " " ) ; } out }
Format expr to SQL string.
Format expr to SQL string .
&self