Add Teradata dialect

Adds base implementation for the Teradata SQL dialect.

Author: iffyio

src/dialect/mod.rs

@@ -30,6 +30,7 @@ mod redshift;
 mod snowflake;
 mod spark;
 mod sqlite;
+mod teradata;
 
 use core::any::{Any, TypeId};
 use core::fmt::Debug;
@@ -54,6 +55,7 @@ pub use self::snowflake::parse_snowflake_stage_name;
 pub use self::snowflake::SnowflakeDialect;
 pub use self::spark::SparkSqlDialect;
 pub use self::sqlite::SQLiteDialect;
+pub use self::teradata::TeradataDialect;
 
 /// Macro for streamlining the creation of derived `Dialect` objects.
 /// The generated struct includes `new()` and `default()` constructors.
@@ -1841,6 +1843,7 @@ pub fn dialect_from_str(dialect_name: impl AsRef<str>) -> Option<Box<dyn Dialect
         "databricks" => Some(Box::new(DatabricksDialect {})),
         "spark" | "sparksql" => Some(Box::new(SparkSqlDialect {})),
         "oracle" => Some(Box::new(OracleDialect {})),
+        "teradata" => Some(Box::new(TeradataDialect {})),
         _ => None,
     }
 }
@@ -1894,6 +1897,8 @@ mod tests {
         assert!(parse_dialect("DuckDb").is::<DuckDbDialect>());
         assert!(parse_dialect("DataBricks").is::<DatabricksDialect>());
         assert!(parse_dialect("databricks").is::<DatabricksDialect>());
+        assert!(parse_dialect("teradata").is::<TeradataDialect>());
+        assert!(parse_dialect("Teradata").is::<TeradataDialect>());
 
         // error cases
         assert!(dialect_from_str("Unknown").is_none());

src/dialect/teradata.rs

@@ -0,0 +1,92 @@
+// 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 [Teradata](https://docs.teradata.com/).
+#[derive(Debug, Default, Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+pub struct TeradataDialect;
+
+impl Dialect for TeradataDialect {
+    /// See <https://docs.teradata.com/r/Enterprise_IntelliFlex_VMware/SQL-Fundamentals/Basic-SQL-Syntax/Object-Names>
+    fn identifier_quote_style(&self, _identifier: &str) -> Option<char> {
+        Some('"')
+    }
+
+    /// See <https://docs.teradata.com/r/Enterprise_IntelliFlex_VMware/SQL-Fundamentals/Basic-SQL-Syntax/Working-with-Unicode-Delimited-Identifiers>
+    fn is_delimited_identifier_start(&self, ch: char) -> bool {
+        ch == '"'
+    }
+
+    /// See <https://docs.teradata.com/r/Enterprise_IntelliFlex_VMware/International-Character-Set-Support/Managing-International-Language-Support/Object-Names/Rules-for-Object-Naming>
+    fn is_identifier_start(&self, ch: char) -> bool {
+        ch.is_alphabetic() || ch == '_' || ch == '#' || ch == '$'
+    }
+
+    // See <https://docs.teradata.com/r/Enterprise_IntelliFlex_VMware/SQL-Fundamentals/Basic-SQL-Syntax/Object-Names>
+    fn is_identifier_part(&self, ch: char) -> bool {
+        ch.is_alphanumeric() || self.is_identifier_start(ch)
+    }
+
+    /// See <https://docs.teradata.com/r/Enterprise_IntelliFlex_VMware/SQL-Data-Manipulation-Language/SELECT-Statements/GROUP-BY-Clause/GROUP-BY-Clause-Syntax>
+    fn supports_group_by_expr(&self) -> bool {
+        true
+    }
+
+    /// Teradata has no native `BOOLEAN` data type.
+    ///
+    /// See <https://docs.teradata.com/r/Enterprise_IntelliFlex_VMware/SQL-Data-Types-and-Literals>
+    fn supports_boolean_literals(&self) -> bool {
+        false
+    }
+
+    /// See <https://docs.teradata.com/r/Enterprise_IntelliFlex_VMware/SQL-Data-Types-and-Literals/Data-Literals/Interval-Literals>
+    fn require_interval_qualifier(&self) -> bool {
+        true
+    }
+
+    /// See <https://docs.teradata.com/r/Enterprise_IntelliFlex_VMware/SQL-Data-Definition-Language-Syntax-and-Examples/Comment-Help-and-Show-Statements/COMMENT-Comment-Placing-Form>
+    fn supports_comment_on(&self) -> bool {
+        true
+    }
+
+    /// See <https://docs.teradata.com/r/Enterprise_IntelliFlex_VMware/SQL-Data-Definition-Language-Syntax-and-Examples/Table-Statements/CREATE-TABLE-and-CREATE-TABLE-AS>
+    fn supports_create_table_select(&self) -> bool {
+        true
+    }
+
+    /// See <https://docs.teradata.com/r/Enterprise_IntelliFlex_VMware/SQL-Stored-Procedures-and-Embedded-SQL/Dynamic-Embedded-SQL-Statements/Dynamic-SQL-Statement-Syntax/EXECUTE-IMMEDIATE>
+    fn supports_execute_immediate(&self) -> bool {
+        true
+    }
+
+    /// See <https://docs.teradata.com/r/Enterprise_IntelliFlex_VMware/SQL-Data-Manipulation-Language/SELECT-Statements/Select-List-Syntax/TOP-Clause>
+    fn supports_top_before_distinct(&self) -> bool {
+        true
+    }
+
+    /// See <https://docs.teradata.com/r/Enterprise_IntelliFlex_VMware/SQL-Functions-Expressions-and-Predicates/Ordered-Analytical/Window-Aggregate-Functions>
+    fn supports_window_function_null_treatment_arg(&self) -> bool {
+        true
+    }
+
+    /// See <https://docs.teradata.com/r/Enterprise_IntelliFlex_VMware/SQL-Data-Types-and-Literals/Data-Literals/Character-String-Literals>
+    fn supports_string_literal_concatenation(&self) -> bool {
+        true
+    }
+}

src/test_utils.rs

@@ -292,6 +292,7 @@ pub fn all_dialects() -> TestedDialects {
         Box::new(DatabricksDialect {}),
         Box::new(ClickHouseDialect {}),
         Box::new(OracleDialect {}),
+        Box::new(TeradataDialect {}),
     ])
 }
 

tests/sqlparser_common.rs

@@ -18180,7 +18180,7 @@ fn test_parse_semantic_view_table_factor() {
 
 #[test]
 fn parse_adjacent_string_literal_concatenation() {
-    let sql = r#"SELECT 'M' "y" 'S' "q" 'l'"#;
+    let sql = r#"SELECT 'M' 'y' 'S' 'q' 'l'"#;
     let dialects = all_dialects_where(|d| d.supports_string_literal_concatenation());
     dialects.one_statement_parses_to(sql, r"SELECT 'MySql'");
 

tests/sqlparser_mysql.rs

@@ -4891,3 +4891,9 @@ fn parse_create_database_with_charset_option_ordering() {
         "CREATE DATABASE mydb DEFAULT CHARACTER SET utf8mb4 DEFAULT COLLATE utf8mb4_unicode_ci",
     );
 }
+
+#[test]
+fn parse_adjacent_string_literal_concatenation() {
+    let sql = r#"SELECT 'M' "y" 'S' "q" 'l'"#;
+    mysql().one_statement_parses_to(sql, r"SELECT 'MySql'");
+}

tests/sqlparser_teradata.rs

@@ -0,0 +1,63 @@
+// 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.
+
+//! Test SQL syntax, specific to [sqlparser::dialect::TeradataDialect].
+
+use sqlparser::dialect::{Dialect, TeradataDialect};
+use test_utils::TestedDialects;
+
+mod test_utils;
+
+fn teradata() -> TestedDialects {
+    TestedDialects::new(vec![Box::new(TeradataDialect)])
+}
+
+#[test]
+fn dialect_methods() {
+    let d: &dyn Dialect = &TeradataDialect;
+    assert_eq!(d.identifier_quote_style("x"), Some('"'));
+    assert!(d.is_delimited_identifier_start('"'));
+    assert!(!d.is_delimited_identifier_start('`'));
+    assert!(d.is_identifier_start('$'));
+    assert!(d.is_identifier_start('#'));
+    assert!(d.is_identifier_part('$'));
+    assert!(d.is_identifier_part('#'));
+    assert!(d.supports_group_by_expr());
+    assert!(!d.supports_boolean_literals());
+    assert!(d.require_interval_qualifier());
+    assert!(d.supports_comment_on());
+    assert!(d.supports_create_table_select());
+    assert!(d.supports_execute_immediate());
+    assert!(d.supports_top_before_distinct());
+    assert!(d.supports_window_function_null_treatment_arg());
+    assert!(d.supports_string_literal_concatenation());
+}
+
+#[test]
+fn parse_identifier() {
+    teradata().verified_stmt(concat!(
+        "SELECT ",
+        "NULL AS foo, ",
+        "NULL AS _bar, ",
+        "NULL AS #baz, ",
+        "NULL AS $qux, ",
+        "NULL AS a$1, ",
+        "NULL AS a#1, ",
+        "NULL AS a_1, ",
+        r#"NULL AS "quoted id""#
+    ));
+}