sqltk_parser/dialect/
mysql.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::{
22    ast::{BinaryOperator, Expr, LockTableType, LockTables, MySqlTableLock, Statement},
23    dialect::Dialect,
24    keywords::Keyword,
25    parser::{Parser, ParserError},
26};
27
28/// A [`Dialect`] for [MySQL](https://www.mysql.com/)
29#[derive(Debug)]
30pub struct MySqlDialect {}
31
32impl Dialect for MySqlDialect {
33    fn is_identifier_start(&self, ch: char) -> bool {
34        // See https://dev.mysql.com/doc/refman/8.0/en/identifiers.html.
35        // Identifiers which begin with a digit are recognized while tokenizing numbers,
36        // so they can be distinguished from exponent numeric literals.
37        ch.is_alphabetic()
38            || ch == '_'
39            || ch == '$'
40            || ch == '@'
41            || ('\u{0080}'..='\u{ffff}').contains(&ch)
42    }
43
44    fn is_identifier_part(&self, ch: char) -> bool {
45        self.is_identifier_start(ch) || ch.is_ascii_digit()
46    }
47
48    fn is_delimited_identifier_start(&self, ch: char) -> bool {
49        ch == '`'
50    }
51
52    fn identifier_quote_style(&self, _identifier: &str) -> Option<char> {
53        Some('`')
54    }
55
56    // See https://dev.mysql.com/doc/refman/8.0/en/string-literals.html#character-escape-sequences
57    fn supports_string_literal_backslash_escape(&self) -> bool {
58        true
59    }
60
61    fn supports_numeric_prefix(&self) -> bool {
62        true
63    }
64
65    fn parse_infix(
66        &self,
67        parser: &mut crate::parser::Parser,
68        expr: &crate::ast::Expr,
69        _precedence: u8,
70    ) -> Option<Result<crate::ast::Expr, ParserError>> {
71        // Parse DIV as an operator
72        if parser.parse_keyword(Keyword::DIV) {
73            Some(Ok(Expr::BinaryOp {
74                left: Box::new(expr.clone()),
75                op: BinaryOperator::MyIntegerDivide,
76                right: Box::new(parser.parse_expr().unwrap()),
77            }))
78        } else {
79            None
80        }
81    }
82
83    fn parse_statement(&self, parser: &mut Parser) -> Option<Result<Statement, ParserError>> {
84        if parser.parse_keywords(&[Keyword::LOCK, Keyword::TABLE]) {
85            Some(parse_lock_tables(parser, false))
86        } else if parser.parse_keywords(&[Keyword::LOCK, Keyword::TABLES]) {
87            Some(parse_lock_tables(parser, true))
88        } else if parser.parse_keywords(&[Keyword::UNLOCK, Keyword::TABLE]) {
89            Some(parse_unlock_tables(parser, false))
90        } else if parser.parse_keywords(&[Keyword::UNLOCK, Keyword::TABLES]) {
91            Some(parse_unlock_tables(parser, true))
92        } else {
93            None
94        }
95    }
96
97    fn require_interval_qualifier(&self) -> bool {
98        true
99    }
100
101    fn supports_limit_comma(&self) -> bool {
102        true
103    }
104
105    /// see <https://dev.mysql.com/doc/refman/8.4/en/create-table-select.html>
106    fn supports_create_table_select(&self) -> bool {
107        true
108    }
109}
110
111/// `LOCK TABLES`
112/// <https://dev.mysql.com/doc/refman/8.0/en/lock-tables.html>
113fn parse_lock_tables(
114    parser: &mut Parser,
115    pluralized_table_keyword: bool,
116) -> Result<Statement, ParserError> {
117    let tables = parser.parse_comma_separated(parse_lock_table)?;
118    Ok(Statement::LockTables(LockTables::MySql {
119        pluralized_table_keyword,
120        tables,
121    }))
122}
123
124// tbl_name [[AS] alias] lock_type
125fn parse_lock_table(parser: &mut Parser) -> Result<MySqlTableLock, ParserError> {
126    let table = parser.parse_object_name(false)?;
127    let alias =
128        parser.parse_optional_alias(&[Keyword::READ, Keyword::WRITE, Keyword::LOW_PRIORITY])?;
129    let lock_type = parse_lock_tables_type(parser)?;
130
131    Ok(MySqlTableLock {
132        table,
133        alias,
134        lock_type: Some(lock_type),
135    })
136}
137
138// READ [LOCAL] | [LOW_PRIORITY] WRITE
139fn parse_lock_tables_type(parser: &mut Parser) -> Result<LockTableType, ParserError> {
140    if parser.parse_keyword(Keyword::READ) {
141        if parser.parse_keyword(Keyword::LOCAL) {
142            Ok(LockTableType::Read { local: true })
143        } else {
144            Ok(LockTableType::Read { local: false })
145        }
146    } else if parser.parse_keyword(Keyword::WRITE) {
147        Ok(LockTableType::Write {
148            low_priority: false,
149        })
150    } else if parser.parse_keywords(&[Keyword::LOW_PRIORITY, Keyword::WRITE]) {
151        Ok(LockTableType::Write { low_priority: true })
152    } else {
153        parser.expected("an lock type in LOCK TABLES", parser.peek_token())
154    }
155}
156
157/// UNLOCK TABLES
158/// <https://dev.mysql.com/doc/refman/8.0/en/lock-tables.html>
159fn parse_unlock_tables(
160    _parser: &mut Parser,
161    pluralized_table: bool,
162) -> Result<Statement, ParserError> {
163    Ok(Statement::UnlockTables(pluralized_table))
164}
sqltk_parser/dialect/mysql.rs

sqltk_parser/dialect/
mysql.rs
