feat: support mysql flavor show processlist shortcut (#6328) (#6379)

* feat: support mysql flavor show processlist shortcut (#6328)

Signed-off-by: codephage. <381510760@qq.com>

* Refactor SHOW PROCESSLIST handling and add tests

Signed-off-by: codephage. <381510760@qq.com>

* add sqlness test

Signed-off-by: codephage. <381510760@qq.com>

* add sqlness test result

Signed-off-by: codephage. <381510760@qq.com>

* fix sqlness test show_processList

Signed-off-by: codephage. <381510760@qq.com>

---------

Signed-off-by: codephage. <381510760@qq.com>

src/sql/src/parsers/show_parser.rs

@@ -25,8 +25,8 @@ use crate::error::{
 use crate::parser::ParserContext;
 use crate::statements::show::{
     ShowColumns, ShowCreateDatabase, ShowCreateFlow, ShowCreateTable, ShowCreateTableVariant,
-    ShowCreateView, ShowDatabases, ShowFlows, ShowIndex, ShowKind, ShowRegion, ShowSearchPath,
-    ShowStatus, ShowTableStatus, ShowTables, ShowVariables, ShowViews,
+    ShowCreateView, ShowDatabases, ShowFlows, ShowIndex, ShowKind, ShowProcessList, ShowRegion,
+    ShowSearchPath, ShowStatus, ShowTableStatus, ShowTables, ShowVariables, ShowViews,
 };
 use crate::statements::statement::Statement;
 
@@ -104,6 +104,8 @@ impl ParserContext<'_> {
                 self.parse_show_columns(true)
             } else if self.consume_token("DATABASES") || self.consume_token("SCHEMAS") {
                 self.parse_show_databases(true)
+            } else if self.consume_token("PROCESSLIST") {
+                self.parse_show_processlist(true)
             } else {
                 self.unsupported(self.peek_token_as_string())
             }
@@ -119,6 +121,8 @@ impl ParserContext<'_> {
             Ok(Statement::ShowStatus(ShowStatus {}))
         } else if self.consume_token("SEARCH_PATH") {
             Ok(Statement::ShowSearchPath(ShowSearchPath {}))
+        } else if self.consume_token("PROCESSLIST") {
+            self.parse_show_processlist(false)
         } else {
             self.unsupported(self.peek_token_as_string())
         }
@@ -571,6 +575,15 @@ impl ParserContext<'_> {
 
         Ok(Statement::ShowFlows(ShowFlows { kind, database }))
     }
+
+    fn parse_show_processlist(&mut self, full: bool) -> Result<Statement> {
+        match self.parser.next_token().token {
+            Token::EOF | Token::SemiColon => {
+                Ok(Statement::ShowProcesslist(ShowProcessList { full }))
+            }
+            _ => self.unsupported(self.peek_token_as_string()),
+        }
+    }
 }
 
 #[cfg(test)]
@@ -1212,4 +1225,29 @@ mod tests {
         );
         assert_eq!(sql, stmts[0].to_string());
     }
+
+    #[test]
+    pub fn test_show_processlist() {
+        let sql = "SHOW PROCESSLIST";
+        let result =
+            ParserContext::create_with_dialect(sql, &GreptimeDbDialect {}, ParseOptions::default());
+        let stmts = result.unwrap();
+        assert_eq!(1, stmts.len());
+        assert_eq!(
+            stmts[0],
+            Statement::ShowProcesslist(ShowProcessList { full: false })
+        );
+        assert_eq!(sql, stmts[0].to_string());
+
+        let sql = "SHOW FULL PROCESSLIST";
+        let result =
+            ParserContext::create_with_dialect(sql, &GreptimeDbDialect {}, ParseOptions::default());
+        let stmts = result.unwrap();
+        assert_eq!(1, stmts.len());
+        assert_eq!(
+            stmts[0],
+            Statement::ShowProcesslist(ShowProcessList { full: true })
+        );
+        assert_eq!(sql, stmts[0].to_string());
+    }
 }

src/sql/src/statements/show.rs

@@ -321,6 +321,23 @@ impl Display for ShowSearchPath {
     }
 }
 
+/// SQL structure for `SHOW PROCESSLIST`.
+#[derive(Debug, Clone, PartialEq, Eq, Visit, VisitMut, Serialize)]
+pub struct ShowProcessList {
+    pub full: bool,
+}
+impl Display for ShowProcessList {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        if self.full {
+            write!(f, "SHOW FULL PROCESSLIST")?;
+        } else {
+            write!(f, "SHOW PROCESSLIST")?;
+        }
+
+        Ok(())
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use std::assert_matches::assert_matches;

src/sql/src/statements/statement.rs

@@ -37,8 +37,8 @@ use crate::statements::query::Query;
 use crate::statements::set_variables::SetVariables;
 use crate::statements::show::{
     ShowColumns, ShowCreateDatabase, ShowCreateFlow, ShowCreateTable, ShowCreateView,
-    ShowDatabases, ShowFlows, ShowIndex, ShowKind, ShowRegion, ShowSearchPath, ShowStatus,
-    ShowTableStatus, ShowTables, ShowVariables, ShowViews,
+    ShowDatabases, ShowFlows, ShowIndex, ShowKind, ShowProcessList, ShowRegion, ShowSearchPath,
+    ShowStatus, ShowTableStatus, ShowTables, ShowVariables, ShowViews,
 };
 use crate::statements::tql::Tql;
 use crate::statements::truncate::TruncateTable;
@@ -141,6 +141,8 @@ pub enum Statement {
     CloseCursor(CloseCursor),
     // KILL <process>
     Kill(Kill),
+    // SHOW PROCESSLIST
+    ShowProcesslist(ShowProcessList),
 }
 
 impl Display for Statement {
@@ -198,6 +200,7 @@ impl Display for Statement {
             Statement::FetchCursor(s) => s.fmt(f),
             Statement::CloseCursor(s) => s.fmt(f),
             Statement::Kill(k) => k.fmt(f),
+            Statement::ShowProcesslist(s) => s.fmt(f),
         }
     }
 }