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sqlparser/dialect/

sqlite.rs

1// Licensed to the Apache Software Foundation (ASF) under one
2// or more contributor license agreements.  See the NOTICE file
3// distributed with this work for additional information
4// regarding copyright ownership.  The ASF licenses this file
5// to you under the Apache License, Version 2.0 (the
6// "License"); you may not use this file except in compliance
7// with the License.  You may obtain a copy of the License at
8//
9//   http://www.apache.org/licenses/LICENSE-2.0
10//
11// Unless required by applicable law or agreed to in writing,
12// software distributed under the License is distributed on an
13// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
14// KIND, either express or implied.  See the License for the
15// specific language governing permissions and limitations
16// under the License.
17
18#[cfg(not(feature = "std"))]
19use alloc::boxed::Box;
20
21use crate::ast::BinaryOperator;
22use crate::ast::{Expr, Statement};
23use crate::dialect::Dialect;
24use crate::keywords::Keyword;
25use crate::parser::{Parser, ParserError};
26
27/// A [`Dialect`] for [SQLite](https://www.sqlite.org)
28///
29/// This dialect allows columns in a
30/// [`CREATE TABLE`](https://sqlite.org/lang_createtable.html) statement with no
31/// type specified, as in `CREATE TABLE t1 (a)`. In the AST, these columns will
32/// have the data type [`Unspecified`](crate::ast::DataType::Unspecified).
33#[derive(Debug, Default, Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord)]
34#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
35pub struct SQLiteDialect {}
36
37impl Dialect for SQLiteDialect {
38    // see https://www.sqlite.org/lang_keywords.html
39    // parse `...`, [...] and "..." as identifier
40    // TODO: support depending on the context tread '...' as identifier too.
41    fn is_delimited_identifier_start(&self, ch: char) -> bool {
42        ch == '`' || ch == '"' || ch == '['
43    }
44
45    fn identifier_quote_style(&self, _identifier: &str) -> Option<char> {
46        Some('`')
47    }
48
49    fn is_identifier_start(&self, ch: char) -> bool {
50        // See https://www.sqlite.org/draft/tokenreq.html
51        ch.is_ascii_lowercase()
52            || ch.is_ascii_uppercase()
53            || ch == '_'
54            || ('\u{007f}'..='\u{ffff}').contains(&ch)
55    }
56
57    fn supports_filter_during_aggregation(&self) -> bool {
58        true
59    }
60
61    fn supports_start_transaction_modifier(&self) -> bool {
62        true
63    }
64
65    fn is_identifier_part(&self, ch: char) -> bool {
66        self.is_identifier_start(ch) || ch.is_ascii_digit()
67    }
68
69    fn parse_statement(&self, parser: &mut Parser) -> Option<Result<Statement, ParserError>> {
70        if parser.parse_keyword(Keyword::REPLACE) {
71            parser.prev_token();
72            Some(parser.parse_insert(parser.get_current_token().clone()))
73        } else {
74            None
75        }
76    }
77
78    fn parse_infix(
79        &self,
80        parser: &mut crate::parser::Parser,
81        expr: &crate::ast::Expr,
82        _precedence: u8,
83    ) -> Option<Result<crate::ast::Expr, ParserError>> {
84        // Parse MATCH and REGEXP as operators
85        // See <https://www.sqlite.org/lang_expr.html#the_like_glob_regexp_match_and_extract_operators>
86        for (keyword, op) in [
87            (Keyword::REGEXP, BinaryOperator::Regexp),
88            (Keyword::MATCH, BinaryOperator::Match),
89        ] {
90            if parser.parse_keyword(keyword) {
91                let left = Box::new(expr.clone());
92                let right = Box::new(parser.parse_expr().unwrap());
93                return Some(Ok(Expr::BinaryOp { left, op, right }));
94            }
95        }
96        None
97    }
98
99    fn supports_in_empty_list(&self) -> bool {
100        true
101    }
102
103    fn supports_limit_comma(&self) -> bool {
104        true
105    }
106
107    fn supports_asc_desc_in_column_definition(&self) -> bool {
108        true
109    }
110
111    fn supports_dollar_placeholder(&self) -> bool {
112        true
113    }
114
115    /// SQLite supports `NOTNULL` as aliases for `IS NOT NULL`
116    /// See: <https://sqlite.org/syntax/expr.html>
117    fn supports_notnull_operator(&self) -> bool {
118        true
119    }
120}