datafusion-sqlparse/src/dialect/clickhouse.rs
2025-02-22 06:52:07 +01:00

97 lines
3 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;
// A [`Dialect`] for [ClickHouse](https://clickhouse.com/).
#[derive(Debug)]
pub struct ClickHouseDialect {}
impl Dialect for ClickHouseDialect {
fn is_identifier_start(&self, ch: char) -> bool {
// See https://clickhouse.com/docs/en/sql-reference/syntax/#syntax-identifiers
ch.is_ascii_lowercase() || ch.is_ascii_uppercase() || ch == '_'
}
fn is_identifier_part(&self, ch: char) -> bool {
self.is_identifier_start(ch) || ch.is_ascii_digit()
}
fn supports_string_literal_backslash_escape(&self) -> bool {
true
}
fn supports_select_wildcard_except(&self) -> bool {
true
}
fn describe_requires_table_keyword(&self) -> bool {
true
}
fn require_interval_qualifier(&self) -> bool {
true
}
fn supports_limit_comma(&self) -> bool {
true
}
fn supports_insert_table_function(&self) -> bool {
true
}
fn supports_insert_format(&self) -> bool {
true
}
fn supports_numeric_literal_underscores(&self) -> bool {
true
}
// ClickHouse uses this for some FORMAT expressions in `INSERT` context, e.g. when inserting
// with FORMAT JSONEachRow a raw JSON key-value expression is valid and expected.
//
// [ClickHouse formats](https://clickhouse.com/docs/en/interfaces/formats)
fn supports_dictionary_syntax(&self) -> bool {
true
}
/// See <https://clickhouse.com/docs/en/sql-reference/functions#higher-order-functions---operator-and-lambdaparams-expr-function>
fn supports_lambda_functions(&self) -> bool {
true
}
fn supports_from_first_select(&self) -> bool {
true
}
/// See <https://clickhouse.com/docs/en/sql-reference/statements/select/order-by>
fn supports_order_by_all(&self) -> bool {
true
}
// See <https://clickhouse.com/docs/en/sql-reference/aggregate-functions/grouping_function#grouping-sets>
fn supports_group_by_expr(&self) -> bool {
true
}
/// See <https://clickhouse.com/docs/en/sql-reference/statements/select/group-by#rollup-modifier>
fn supports_group_by_with_modifier(&self) -> bool {
true
}
}