mirror of
https://github.com/apache/datafusion-sqlparser-rs.git
synced 2025-08-04 14:28:22 +00:00
77 lines
2.9 KiB
Rust
77 lines
2.9 KiB
Rust
// Licensed to the Apache Software Foundation (ASF) under one
|
|
// or more contributor license agreements. See the NOTICE file
|
|
// distributed with this work for additional information
|
|
// regarding copyright ownership. The ASF licenses this file
|
|
// to you under the Apache License, Version 2.0 (the
|
|
// "License"); you may not use this file except in compliance
|
|
// with the License. You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing,
|
|
// software distributed under the License is distributed on an
|
|
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
|
|
// KIND, either express or implied. See the License for the
|
|
// specific language governing permissions and limitations
|
|
// under the License.
|
|
|
|
use crate::dialect::Dialect;
|
|
use core::iter::Peekable;
|
|
use core::str::Chars;
|
|
|
|
use super::PostgreSqlDialect;
|
|
|
|
/// A [`Dialect`] for [RedShift](https://aws.amazon.com/redshift/)
|
|
#[derive(Debug)]
|
|
pub struct RedshiftSqlDialect {}
|
|
|
|
// In most cases the redshift dialect is identical to [`PostgresSqlDialect`].
|
|
//
|
|
// Notable differences:
|
|
// 1. Redshift treats brackets `[` and `]` differently. For example, `SQL SELECT a[1][2] FROM b`
|
|
// in the Postgres dialect, the query will be parsed as an array, while in the Redshift dialect it will
|
|
// be a json path
|
|
impl Dialect for RedshiftSqlDialect {
|
|
fn is_delimited_identifier_start(&self, ch: char) -> bool {
|
|
ch == '"' || ch == '['
|
|
}
|
|
|
|
/// Determine if quoted characters are proper for identifier
|
|
/// It's needed to distinguish treating square brackets as quotes from
|
|
/// treating them as json path. If there is identifier then we assume
|
|
/// there is no json path.
|
|
fn is_proper_identifier_inside_quotes(&self, mut chars: Peekable<Chars<'_>>) -> bool {
|
|
chars.next();
|
|
let mut not_white_chars = chars.skip_while(|ch| ch.is_whitespace()).peekable();
|
|
if let Some(&ch) = not_white_chars.peek() {
|
|
return self.is_identifier_start(ch);
|
|
}
|
|
false
|
|
}
|
|
|
|
fn is_identifier_start(&self, ch: char) -> bool {
|
|
// Extends Postgres dialect with sharp
|
|
PostgreSqlDialect {}.is_identifier_start(ch) || ch == '#'
|
|
}
|
|
|
|
fn is_identifier_part(&self, ch: char) -> bool {
|
|
// Extends Postgres dialect with sharp
|
|
PostgreSqlDialect {}.is_identifier_part(ch) || ch == '#'
|
|
}
|
|
|
|
/// redshift has `CONVERT(type, value)` instead of `CONVERT(value, type)`
|
|
/// <https://docs.aws.amazon.com/redshift/latest/dg/r_CONVERT_function.html>
|
|
fn convert_type_before_value(&self) -> bool {
|
|
true
|
|
}
|
|
|
|
fn supports_connect_by(&self) -> bool {
|
|
true
|
|
}
|
|
|
|
/// Redshift expects the `TOP` option before the `ALL/DISTINCT` option:
|
|
/// <https://docs.aws.amazon.com/redshift/latest/dg/r_SELECT_list.html#r_SELECT_list-parameters>
|
|
fn supports_top_before_distinct(&self) -> bool {
|
|
true
|
|
}
|
|
}
|