fix: only require DESCRIBE TABLE for Snowflake and ClickHouse diale…

…ct (#1386)

src/dialect/clickhouse.rs

@@ -33,4 +33,8 @@ impl Dialect for ClickHouseDialect {
  fn supports_select_wildcard_except(&self) -> bool {
  true
  }
+
+ fn describe_requires_table_keyword(&self) -> bool {
+ true
+ }
 }

src/dialect/mod.rs

@@ -485,9 +485,20 @@ pub trait Dialect: Debug + Any {
  }
  }
 
+ /// Returns the precedence when the precedence is otherwise unknown
  fn prec_unknown(&self) -> u8 {
  0
  }
+
+ /// Returns true if this dialect requires the `TABLE` keyword after `DESCRIBE`
+ ///
+ /// Defaults to false.
+ ///
+ /// If true, the following statement is valid: `DESCRIBE TABLE my_table`
+ /// If false, the following statements are valid: `DESCRIBE my_table` and `DESCRIBE table`
+ fn describe_requires_table_keyword(&self) -> bool {
+ false
+ }
 }
 
 /// This represents the operators for which precedence must be defined

src/dialect/snowflake.rs

@@ -154,6 +154,10 @@ impl Dialect for SnowflakeDialect {
  _ => None,
  }
  }
+
+ fn describe_requires_table_keyword(&self) -> bool {
+ true
+ }
 }
 
 /// Parse snowflake create table statement.

src/parser/mod.rs

@@ -8185,15 +8185,20 @@ impl<'a> Parser<'a> {
  format,
  }),
  _ => {
- let mut hive_format = None;
- match self.parse_one_of_keywords(&[Keyword::EXTENDED, Keyword::FORMATTED]) {
- Some(Keyword::EXTENDED) => hive_format = Some(HiveDescribeFormat::Extended),
- Some(Keyword::FORMATTED) => hive_format = Some(HiveDescribeFormat::Formatted),
- _ => {}
- }
+ let hive_format =
+ match self.parse_one_of_keywords(&[Keyword::EXTENDED, Keyword::FORMATTED]) {
+ Some(Keyword::EXTENDED) => Some(HiveDescribeFormat::Extended),
+ Some(Keyword::FORMATTED) => Some(HiveDescribeFormat::Formatted),
+ _ => None,
+ };
+
+ let has_table_keyword = if self.dialect.describe_requires_table_keyword() {
+ // only allow to use TABLE keyword for DESC|DESCRIBE statement
+ self.parse_keyword(Keyword::TABLE)
+ } else {
+ false
+ };
 
- // only allow to use TABLE keyword for DESC|DESCRIBE statement
- let has_table_keyword = self.parse_keyword(Keyword::TABLE);
  let table_name = self.parse_object_name(false)?;
  Ok(Statement::ExplainTable {
  describe_alias,

tests/sqlparser_clickhouse.rs

@@ -1376,6 +1376,36 @@ fn parse_select_table_function_settings() {
  }
 }
 
+#[test]
+fn explain_describe() {
+ clickhouse().verified_stmt("DESCRIBE test.table");
+ clickhouse().verified_stmt("DESCRIBE TABLE test.table");
+}
+
+#[test]
+fn explain_desc() {
+ clickhouse().verified_stmt("DESC test.table");
+ clickhouse().verified_stmt("DESC TABLE test.table");
+}
+
+#[test]
+fn parse_explain_table() {
+ match clickhouse().verified_stmt("EXPLAIN TABLE test_identifier") {
+ Statement::ExplainTable {
+ describe_alias,
+ hive_format,
+ has_table_keyword,
+ table_name,
+ } => {
+ pretty_assertions::assert_eq!(describe_alias, DescribeAlias::Explain);
+ pretty_assertions::assert_eq!(hive_format, None);
+ pretty_assertions::assert_eq!(has_table_keyword, true);
+ pretty_assertions::assert_eq!("test_identifier", table_name.to_string());
+ }
+ _ => panic!("Unexpected Statement, must be ExplainTable"),
+ }
+}
+
 fn clickhouse() -> TestedDialects {
  TestedDialects {
  dialects: vec![Box::new(ClickHouseDialect {})],

tests/sqlparser_common.rs

@@ -4301,29 +4301,16 @@ fn parse_explain_table() {
  validate_explain("EXPLAIN test_identifier", DescribeAlias::Explain, false);
  validate_explain("DESCRIBE test_identifier", DescribeAlias::Describe, false);
  validate_explain("DESC test_identifier", DescribeAlias::Desc, false);
- validate_explain(
- "EXPLAIN TABLE test_identifier",
- DescribeAlias::Explain,
- true,
- );
- validate_explain(
- "DESCRIBE TABLE test_identifier",
- DescribeAlias::Describe,
- true,
- );
- validate_explain("DESC TABLE test_identifier", DescribeAlias::Desc, true);
 }
 
 #[test]
 fn explain_describe() {
  verified_stmt("DESCRIBE test.table");
- verified_stmt("DESCRIBE TABLE test.table");
 }
 
 #[test]
 fn explain_desc() {
  verified_stmt("DESC test.table");
- verified_stmt("DESC TABLE test.table");
 }
 
 #[test]

tests/sqlparser_hive.rs

@@ -21,7 +21,7 @@ use sqlparser::ast::{
  UnaryOperator, Value,
 };
 use sqlparser::dialect::{GenericDialect, HiveDialect, MsSqlDialect};
-use sqlparser::parser::{ParserError, ParserOptions};
+use sqlparser::parser::ParserError;
 use sqlparser::test_utils::*;
 
 #[test]
@@ -35,18 +35,11 @@ fn parse_table_create() {
  hive().verified_stmt(serdeproperties);
 }
 
-fn generic(options: Option<ParserOptions>) -> TestedDialects {
- TestedDialects {
- dialects: vec![Box::new(GenericDialect {})],
- options,
- }
-}
-
 #[test]
 fn parse_describe() {
- let describe = r#"DESCRIBE namespace.`table`"#;
- hive().verified_stmt(describe);
- generic(None).verified_stmt(describe);
+ hive_and_generic().verified_stmt(r#"DESCRIBE namespace.`table`"#);
+ hive_and_generic().verified_stmt(r#"DESCRIBE namespace.table"#);
+ hive_and_generic().verified_stmt(r#"DESCRIBE table"#);
 }
 
 #[test]
@@ -414,3 +407,10 @@ fn hive() -> TestedDialects {
  options: None,
  }
 }
+
+fn hive_and_generic() -> TestedDialects {
+ TestedDialects {
+ dialects: vec![Box::new(HiveDialect {}), Box::new(GenericDialect {})],
+ options: None,
+ }
+}

tests/sqlparser_snowflake.rs

@@ -2292,3 +2292,33 @@ fn test_parse_position() {
  snowflake().verified_query("SELECT position('an', 'banana', 1)");
  snowflake().verified_query("SELECT n, h, POSITION(n IN h) FROM pos");
 }
+
+#[test]
+fn explain_describe() {
+ snowflake().verified_stmt("DESCRIBE test.table");
+ snowflake().verified_stmt("DESCRIBE TABLE test.table");
+}
+
+#[test]
+fn explain_desc() {
+ snowflake().verified_stmt("DESC test.table");
+ snowflake().verified_stmt("DESC TABLE test.table");
+}
+
+#[test]
+fn parse_explain_table() {
+ match snowflake().verified_stmt("EXPLAIN TABLE test_identifier") {
+ Statement::ExplainTable {
+ describe_alias,
+ hive_format,
+ has_table_keyword,
+ table_name,
+ } => {
+ assert_eq!(describe_alias, DescribeAlias::Explain);
+ assert_eq!(hive_format, None);
+ assert_eq!(has_table_keyword, true);
+ assert_eq!("test_identifier", table_name.to_string());
+ }
+ _ => panic!("Unexpected Statement, must be ExplainTable"),
+ }
+}