sqlparser/dialect/
postgresql.rs

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16// under the License.
17
18// Licensed under the Apache License, Version 2.0 (the "License");
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22// http://www.apache.org/licenses/LICENSE-2.0
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25// distributed under the License is distributed on an "AS IS" BASIS,
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27// See the License for the specific language governing permissions and
28// limitations under the License.
29use log::debug;
30
31use crate::dialect::{Dialect, Precedence};
32use crate::keywords::Keyword;
33use crate::parser::{Parser, ParserError};
34use crate::tokenizer::Token;
35
36use super::keywords::RESERVED_FOR_IDENTIFIER;
37
38/// A [`Dialect`] for [PostgreSQL](https://www.postgresql.org/)
39#[derive(Debug, Default, Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord)]
40#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
41pub struct PostgreSqlDialect {}
42
43const PERIOD_PREC: u8 = 200;
44const DOUBLE_COLON_PREC: u8 = 140;
45const BRACKET_PREC: u8 = 130;
46const COLLATE_PREC: u8 = 120;
47const AT_TZ_PREC: u8 = 110;
48const CARET_PREC: u8 = 100;
49const MUL_DIV_MOD_OP_PREC: u8 = 90;
50const PLUS_MINUS_PREC: u8 = 80;
51// there's no XOR operator in PostgreSQL, but support it here to avoid breaking tests
52const XOR_PREC: u8 = 75;
53const PG_OTHER_PREC: u8 = 70;
54const BETWEEN_LIKE_PREC: u8 = 60;
55const EQ_PREC: u8 = 50;
56const IS_PREC: u8 = 40;
57const NOT_PREC: u8 = 30;
58const AND_PREC: u8 = 20;
59const OR_PREC: u8 = 10;
60
61impl Dialect for PostgreSqlDialect {
62    fn identifier_quote_style(&self, _identifier: &str) -> Option<char> {
63        Some('"')
64    }
65
66    fn is_delimited_identifier_start(&self, ch: char) -> bool {
67        ch == '"' // Postgres does not support backticks to quote identifiers
68    }
69
70    fn is_identifier_start(&self, ch: char) -> bool {
71        ch.is_alphabetic() || ch == '_' ||
72        // PostgreSQL implements Unicode characters in identifiers.
73        !ch.is_ascii()
74    }
75
76    fn is_identifier_part(&self, ch: char) -> bool {
77        ch.is_alphabetic() || ch.is_ascii_digit() || ch == '$' || ch == '_'  ||
78        // PostgreSQL implements Unicode characters in identifiers.
79        !ch.is_ascii()
80    }
81
82    fn supports_unicode_string_literal(&self) -> bool {
83        true
84    }
85
86    fn is_reserved_for_identifier(&self, kw: Keyword) -> bool {
87        if matches!(kw, Keyword::INTERVAL) {
88            false
89        } else {
90            RESERVED_FOR_IDENTIFIER.contains(&kw)
91        }
92    }
93
94    /// See <https://www.postgresql.org/docs/current/sql-createoperator.html>
95    fn is_custom_operator_part(&self, ch: char) -> bool {
96        matches!(
97            ch,
98            '+' | '-'
99                | '*'
100                | '/'
101                | '<'
102                | '>'
103                | '='
104                | '~'
105                | '!'
106                | '@'
107                | '#'
108                | '%'
109                | '^'
110                | '&'
111                | '|'
112                | '`'
113                | '?'
114        )
115    }
116
117    fn get_next_precedence(&self, parser: &Parser) -> Option<Result<u8, ParserError>> {
118        let token = parser.peek_token_ref();
119        debug!("get_next_precedence() {token:?}");
120
121        // we only return some custom value here when the behaviour (not merely the numeric value) differs
122        // from the default implementation
123        match &token.token {
124            Token::Word(w)
125                if w.keyword == Keyword::COLLATE && !parser.in_column_definition_state() =>
126            {
127                Some(Ok(COLLATE_PREC))
128            }
129            Token::LBracket => Some(Ok(BRACKET_PREC)),
130            Token::Arrow
131            | Token::LongArrow
132            | Token::HashArrow
133            | Token::HashLongArrow
134            | Token::AtArrow
135            | Token::ArrowAt
136            | Token::HashMinus
137            | Token::AtQuestion
138            | Token::AtAt
139            | Token::Question
140            | Token::QuestionAnd
141            | Token::QuestionPipe
142            | Token::ExclamationMark
143            | Token::Overlap
144            | Token::CaretAt
145            | Token::StringConcat
146            | Token::Sharp
147            | Token::ShiftRight
148            | Token::ShiftLeft
149            | Token::CustomBinaryOperator(_) => Some(Ok(PG_OTHER_PREC)),
150            // lowest prec to prevent it from turning into a binary op
151            Token::Colon => Some(Ok(self.prec_unknown())),
152            _ => None,
153        }
154    }
155
156    fn supports_filter_during_aggregation(&self) -> bool {
157        true
158    }
159
160    fn supports_group_by_expr(&self) -> bool {
161        true
162    }
163
164    fn prec_value(&self, prec: Precedence) -> u8 {
165        match prec {
166            Precedence::Period => PERIOD_PREC,
167            Precedence::DoubleColon => DOUBLE_COLON_PREC,
168            Precedence::AtTz => AT_TZ_PREC,
169            Precedence::MulDivModOp => MUL_DIV_MOD_OP_PREC,
170            Precedence::PlusMinus => PLUS_MINUS_PREC,
171            Precedence::Xor => XOR_PREC,
172            Precedence::Ampersand => PG_OTHER_PREC,
173            Precedence::Caret => CARET_PREC,
174            Precedence::Pipe => PG_OTHER_PREC,
175            Precedence::Colon => PG_OTHER_PREC,
176            Precedence::Between => BETWEEN_LIKE_PREC,
177            Precedence::Eq => EQ_PREC,
178            Precedence::Like => BETWEEN_LIKE_PREC,
179            Precedence::Is => IS_PREC,
180            Precedence::PgOther => PG_OTHER_PREC,
181            Precedence::UnaryNot => NOT_PREC,
182            Precedence::And => AND_PREC,
183            Precedence::Or => OR_PREC,
184        }
185    }
186
187    fn allow_extract_custom(&self) -> bool {
188        true
189    }
190
191    fn allow_extract_single_quotes(&self) -> bool {
192        true
193    }
194
195    fn supports_create_index_with_clause(&self) -> bool {
196        true
197    }
198
199    /// see <https://www.postgresql.org/docs/current/sql-explain.html>
200    fn supports_explain_with_utility_options(&self) -> bool {
201        true
202    }
203
204    /// see <https://www.postgresql.org/docs/current/sql-listen.html>
205    /// see <https://www.postgresql.org/docs/current/sql-unlisten.html>
206    /// see <https://www.postgresql.org/docs/current/sql-notify.html>
207    fn supports_listen_notify(&self) -> bool {
208        true
209    }
210
211    /// see <https://www.postgresql.org/docs/13/functions-math.html>
212    fn supports_factorial_operator(&self) -> bool {
213        true
214    }
215
216    fn supports_bitwise_shift_operators(&self) -> bool {
217        true
218    }
219
220    /// see <https://www.postgresql.org/docs/current/sql-comment.html>
221    fn supports_comment_on(&self) -> bool {
222        true
223    }
224
225    /// See <https://www.postgresql.org/docs/current/sql-load.html>
226    fn supports_load_extension(&self) -> bool {
227        true
228    }
229
230    /// See <https://www.postgresql.org/docs/current/functions-json.html>
231    ///
232    /// Required to support the colon in:
233    /// ```sql
234    /// SELECT json_object('a': 'b')
235    /// ```
236    fn supports_named_fn_args_with_colon_operator(&self) -> bool {
237        true
238    }
239
240    /// See <https://www.postgresql.org/docs/current/functions-json.html>
241    ///
242    /// Required to support the label in:
243    /// ```sql
244    /// SELECT json_object('label': 'value')
245    /// ```
246    fn supports_named_fn_args_with_expr_name(&self) -> bool {
247        true
248    }
249
250    /// Return true if the dialect supports empty projections in SELECT statements
251    ///
252    /// Example
253    /// ```sql
254    /// SELECT from table_name
255    /// ```
256    fn supports_empty_projections(&self) -> bool {
257        true
258    }
259
260    fn supports_nested_comments(&self) -> bool {
261        true
262    }
263
264    fn supports_string_escape_constant(&self) -> bool {
265        true
266    }
267
268    fn supports_numeric_literal_underscores(&self) -> bool {
269        true
270    }
271
272    /// See: <https://www.postgresql.org/docs/current/arrays.html#ARRAYS-DECLARATION>
273    fn supports_array_typedef_with_brackets(&self) -> bool {
274        true
275    }
276
277    fn supports_geometric_types(&self) -> bool {
278        true
279    }
280
281    fn supports_set_names(&self) -> bool {
282        true
283    }
284
285    fn supports_alter_column_type_using(&self) -> bool {
286        true
287    }
288
289    /// Postgres supports `NOTNULL` as an alias for `IS NOT NULL`
290    /// See: <https://www.postgresql.org/docs/17/functions-comparison.html>
291    fn supports_notnull_operator(&self) -> bool {
292        true
293    }
294
295    /// [Postgres] supports optional field and precision options for `INTERVAL` data type.
296    ///
297    /// [Postgres]: https://www.postgresql.org/docs/17/datatype-datetime.html
298    fn supports_interval_options(&self) -> bool {
299        true
300    }
301
302    fn supports_insert_table_alias(&self) -> bool {
303        true
304    }
305
306    fn supports_create_table_like_parenthesized(&self) -> bool {
307        true
308    }
309
310    fn supports_select_wildcard_with_alias(&self) -> bool {
311        true
312    }
313
314    fn supports_comma_separated_trim(&self) -> bool {
315        true
316    }
317
318    fn supports_xml_expressions(&self) -> bool {
319        true
320    }
321}
sqlparser/dialect/postgresql.rs

sqlparser/dialect/
postgresql.rs
