feat: FLOWS table in information_schema&SHOW FLOWS (#4386)

* feat(WIP): flow info table

refactor: better err handling&log

feat: add flow metadata to info schema provider

feat(WIP): info_schema.flows

feat: info_schema.flows table

* fix: err after rebase

* fix: wrong comparsion op

* feat: SHOW FLOWS&tests

* refactor: per review

* chore: unused

* refactor: json error

* chore: per review

* test: sqlness

* chore: rm inline error

* refactor: per review

src/sql/src/parsers/show_parser.rs

@@ -21,8 +21,8 @@ use crate::error::{
 };
 use crate::parser::ParserContext;
 use crate::statements::show::{
-    ShowColumns, ShowCreateFlow, ShowCreateTable, ShowCreateView, ShowDatabases, ShowIndex,
-    ShowKind, ShowStatus, ShowTableStatus, ShowTables, ShowVariables, ShowViews,
+    ShowColumns, ShowCreateFlow, ShowCreateTable, ShowCreateView, ShowDatabases, ShowFlows,
+    ShowIndex, ShowKind, ShowStatus, ShowTableStatus, ShowTables, ShowVariables, ShowViews,
 };
 use crate::statements::statement::Statement;
 
@@ -46,6 +46,8 @@ impl<'a> ParserContext<'a> {
             }
         } else if self.consume_token("VIEWS") {
             self.parse_show_views()
+        } else if self.consume_token("FLOWS") {
+            self.parse_show_flows()
         } else if self.matches_keyword(Keyword::CHARSET) {
             self.parser.next_token();
             Ok(Statement::ShowCharset(self.parse_show_kind()?))
@@ -442,7 +444,7 @@ impl<'a> ParserContext<'a> {
                 }));
             }
 
-            // SHOW VIEWS [in | FROM] [DATABASE]
+            // SHOW FLOWS [in | FROM] [DATABASE]
             Token::Word(w) => match w.keyword {
                 Keyword::IN | Keyword::FROM => self.parse_db_name()?,
                 _ => None,
@@ -454,6 +456,28 @@ impl<'a> ParserContext<'a> {
 
         Ok(Statement::ShowViews(ShowViews { kind, database }))
     }
+
+    fn parse_show_flows(&mut self) -> Result<Statement> {
+        let database = match self.parser.peek_token().token {
+            Token::EOF | Token::SemiColon => {
+                return Ok(Statement::ShowFlows(ShowFlows {
+                    kind: ShowKind::All,
+                    database: None,
+                }));
+            }
+
+            // SHOW FLOWS [in | FROM] [DATABASE]
+            Token::Word(w) => match w.keyword {
+                Keyword::IN | Keyword::FROM => self.parse_db_name()?,
+                _ => None,
+            },
+            _ => None,
+        };
+
+        let kind = self.parse_show_kind()?;
+
+        Ok(Statement::ShowFlows(ShowFlows { kind, database }))
+    }
 }
 
 #[cfg(test)]
@@ -1000,4 +1024,38 @@ mod tests {
         );
         assert_eq!(sql, stmts[0].to_string());
     }
+
+    #[test]
+    pub fn test_show_flows() {
+        let sql = "SHOW FLOWS";
+        let result =
+            ParserContext::create_with_dialect(sql, &GreptimeDbDialect {}, ParseOptions::default());
+        let stmts = result.unwrap();
+        assert_eq!(1, stmts.len());
+        assert_eq!(
+            stmts[0],
+            Statement::ShowFlows(ShowFlows {
+                kind: ShowKind::All,
+                database: None,
+            })
+        );
+        assert_eq!(sql, stmts[0].to_string());
+    }
+
+    #[test]
+    pub fn test_show_flows_in_db() {
+        let sql = "SHOW FLOWS IN d1";
+        let result =
+            ParserContext::create_with_dialect(sql, &GreptimeDbDialect {}, ParseOptions::default());
+        let stmts = result.unwrap();
+        assert_eq!(1, stmts.len());
+        assert_eq!(
+            stmts[0],
+            Statement::ShowFlows(ShowFlows {
+                kind: ShowKind::All,
+                database: Some("d1".to_string()),
+            })
+        );
+        assert_eq!(sql, stmts[0].to_string());
+    }
 }

src/sql/src/statements/show.rs

@@ -187,6 +187,25 @@ impl Display for ShowCreateFlow {
     }
 }
 
+/// SQL structure for `SHOW FLOWS`.
+#[derive(Debug, Clone, PartialEq, Eq, Visit, VisitMut)]
+pub struct ShowFlows {
+    pub kind: ShowKind,
+    pub database: Option<String>,
+}
+
+impl Display for ShowFlows {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "SHOW FLOWS")?;
+        if let Some(database) = &self.database {
+            write!(f, " IN {database}")?;
+        }
+        format_kind!(self, f);
+
+        Ok(())
+    }
+}
+
 /// SQL structure for `SHOW CREATE VIEW`.
 #[derive(Debug, Clone, PartialEq, Eq, Visit, VisitMut)]
 pub struct ShowCreateView {
@@ -535,6 +554,49 @@ SHOW VIEWS"#,
         }
     }
 
+    #[test]
+    fn test_display_show_flows() {
+        let sql = r"show flows in d1;";
+        let stmts: Vec<Statement> =
+            ParserContext::create_with_dialect(sql, &GreptimeDbDialect {}, ParseOptions::default())
+                .unwrap();
+        assert_eq!(1, stmts.len());
+        assert_matches!(&stmts[0], Statement::ShowFlows { .. });
+        match &stmts[0] {
+            Statement::ShowFlows(show) => {
+                let new_sql = format!("\n{}", show);
+                assert_eq!(
+                    r#"
+SHOW FLOWS IN d1"#,
+                    &new_sql
+                );
+            }
+            _ => {
+                unreachable!();
+            }
+        }
+
+        let sql = r"show flows;";
+        let stmts: Vec<Statement> =
+            ParserContext::create_with_dialect(sql, &GreptimeDbDialect {}, ParseOptions::default())
+                .unwrap();
+        assert_eq!(1, stmts.len());
+        assert_matches!(&stmts[0], Statement::ShowFlows { .. });
+        match &stmts[0] {
+            Statement::ShowFlows(show) => {
+                let new_sql = format!("\n{}", show);
+                assert_eq!(
+                    r#"
+SHOW FLOWS"#,
+                    &new_sql
+                );
+            }
+            _ => {
+                unreachable!("{:?}", &stmts[0]);
+            }
+        }
+    }
+
     #[test]
     fn test_display_show_databases() {
         let sql = r"show databases;";

src/sql/src/statements/statement.rs

@@ -31,8 +31,8 @@ use crate::statements::insert::Insert;
 use crate::statements::query::Query;
 use crate::statements::set_variables::SetVariables;
 use crate::statements::show::{
-    ShowColumns, ShowCreateFlow, ShowCreateTable, ShowCreateView, ShowDatabases, ShowIndex,
-    ShowKind, ShowStatus, ShowTableStatus, ShowTables, ShowVariables, ShowViews,
+    ShowColumns, ShowCreateFlow, ShowCreateTable, ShowCreateView, ShowDatabases, ShowFlows,
+    ShowIndex, ShowKind, ShowStatus, ShowTableStatus, ShowTables, ShowVariables, ShowViews,
 };
 use crate::statements::tql::Tql;
 use crate::statements::truncate::TruncateTable;
@@ -87,6 +87,8 @@ pub enum Statement {
     ShowCreateTable(ShowCreateTable),
     // SHOW CREATE FLOW
     ShowCreateFlow(ShowCreateFlow),
+    /// SHOW FLOWS
+    ShowFlows(ShowFlows),
     // SHOW CREATE VIEW
     ShowCreateView(ShowCreateView),
     // SHOW STATUS
@@ -133,6 +135,7 @@ impl Display for Statement {
             Statement::ShowIndex(s) => s.fmt(f),
             Statement::ShowCreateTable(s) => s.fmt(f),
             Statement::ShowCreateFlow(s) => s.fmt(f),
+            Statement::ShowFlows(s) => s.fmt(f),
             Statement::ShowCreateView(s) => s.fmt(f),
             Statement::ShowViews(s) => s.fmt(f),
             Statement::ShowStatus(s) => s.fmt(f),