feat: Support CLOSE (cursors) (apache#515)

Author: ovr

src/ast/mod.rs

@@ -804,6 +804,11 @@ pub enum Statement {
         /// VALUES a vector of values to be copied
         values: Vec<Option<String>>,
     },
+    /// Close - closes the portal underlying an open cursor.
+    Close {
+        /// Cursor name
+        cursor: CloseCursor,
+    },
     /// UPDATE
     Update {
         /// TABLE
@@ -1393,6 +1398,11 @@ impl fmt::Display for Statement {
                 }
                 Ok(())
             }
+            Statement::Close { cursor } => {
+                write!(f, "CLOSE {}", cursor)?;
+
+                Ok(())
+            }
             Statement::CreateDatabase {
                 db_name,
                 if_not_exists,
@@ -2158,6 +2168,22 @@ impl fmt::Display for FunctionArg {
     }
 }
 
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+pub enum CloseCursor {
+    All,
+    Specific { name: Ident },
+}
+
+impl fmt::Display for CloseCursor {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            CloseCursor::All => write!(f, "ALL"),
+            CloseCursor::Specific { name } => write!(f, "{}", name),
+        }
+    }
+}
+
 /// A function call
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]

src/parser.rs

@@ -174,6 +174,7 @@ impl<'a> Parser<'a> {
                 Keyword::UPDATE => Ok(self.parse_update()?),
                 Keyword::ALTER => Ok(self.parse_alter()?),
                 Keyword::COPY => Ok(self.parse_copy()?),
+                Keyword::CLOSE => Ok(self.parse_close()?),
                 Keyword::SET => Ok(self.parse_set()?),
                 Keyword::SHOW => Ok(self.parse_show()?),
                 Keyword::GRANT => Ok(self.parse_grant()?),
@@ -2563,6 +2564,18 @@ impl<'a> Parser<'a> {
         })
     }
 
+    pub fn parse_close(&mut self) -> Result<Statement, ParserError> {
+        let cursor = if self.parse_keyword(Keyword::ALL) {
+            CloseCursor::All
+        } else {
+            let name = self.parse_identifier()?;
+
+            CloseCursor::Specific { name }
+        };
+
+        Ok(Statement::Close { cursor })
+    }
+
     fn parse_copy_option(&mut self) -> Result<CopyOption, ParserError> {
         let ret = match self.parse_one_of_keywords(&[
             Keyword::FORMAT,

tests/sqlparser_common.rs

@@ -20,6 +20,7 @@
 
 #[macro_use]
 mod test_utils;
+
 use matches::assert_matches;
 use sqlparser::ast::*;
 use sqlparser::dialect::{
@@ -28,6 +29,7 @@ use sqlparser::dialect::{
 };
 use sqlparser::keywords::ALL_KEYWORDS;
 use sqlparser::parser::{Parser, ParserError};
+
 use test_utils::{
     all_dialects, expr_from_projection, join, number, only, table, table_alias, TestedDialects,
 };
@@ -4944,3 +4946,23 @@ fn parse_discard() {
         _ => unreachable!(),
     }
 }
+
+#[test]
+fn parse_cursor() {
+    let sql = r#"CLOSE my_cursor"#;
+    match verified_stmt(sql) {
+        Statement::Close { cursor } => assert_eq!(
+            cursor,
+            CloseCursor::Specific {
+                name: Ident::new("my_cursor"),
+            }
+        ),
+        _ => unreachable!(),
+    }
+
+    let sql = r#"CLOSE ALL"#;
+    match verified_stmt(sql) {
+        Statement::Close { cursor } => assert_eq!(cursor, CloseCursor::All),
+        _ => unreachable!(),
+    }
+}