feat: add show views & desc view (#14926)

* add show views & desc view

* replace useless use of `format!`

* fix error & add test case

* rust fmt

* add logic tests

* add more logic tests

* move desc view test case to package 05_ddl

---------

Co-authored-by: TCeason <33082201+TCeason@users.noreply.github.com>

Author: blackstar-baba

src/query/ast/src/ast/format/ast_format.rs

@@ -1723,6 +1723,33 @@ impl<'ast> Visitor<'ast> for AstFormatVisitor {
         self.children.push(node);
     }
 
+    fn visit_show_views(&mut self, stmt: &'ast ShowViewsStmt) {
+        let mut children = Vec::new();
+        if let Some(database) = &stmt.database {
+            let database_name = format!("Database {}", database);
+            let database_format_ctx = AstFormatContext::new(database_name);
+            let database_node = FormatTreeNode::new(database_format_ctx);
+            children.push(database_node);
+        }
+        if let Some(limit) = &stmt.limit {
+            self.visit_show_limit(limit);
+            children.push(self.children.pop().unwrap());
+        }
+        let name = "ShowViews".to_string();
+        let format_ctx = AstFormatContext::with_children(name, children.len());
+        let node = FormatTreeNode::with_children(format_ctx, children);
+        self.children.push(node);
+    }
+
+    fn visit_describe_view(&mut self, stmt: &'ast DescribeViewStmt) {
+        self.visit_table_ref(&stmt.catalog, &stmt.database, &stmt.view);
+        let child = self.children.pop().unwrap();
+        let name = "DescribeView".to_string();
+        let format_ctx = AstFormatContext::with_children(name, 1);
+        let node = FormatTreeNode::with_children(format_ctx, vec![child]);
+        self.children.push(node);
+    }
+
     fn visit_create_stream(&mut self, stmt: &'ast CreateStreamStmt) {
         let mut children = Vec::new();
         self.visit_table_ref(&stmt.catalog, &stmt.database, &stmt.stream);

src/query/ast/src/ast/statements/statement.rs

@@ -154,6 +154,8 @@ pub enum Statement {
     CreateView(CreateViewStmt),
     AlterView(AlterViewStmt),
     DropView(DropViewStmt),
+    ShowViews(ShowViewsStmt),
+    DescribeView(DescribeViewStmt),
 
     // Streams
     CreateStream(CreateStreamStmt),
@@ -549,6 +551,8 @@ impl Display for Statement {
             Statement::CreateView(stmt) => write!(f, "{stmt}")?,
             Statement::AlterView(stmt) => write!(f, "{stmt}")?,
             Statement::DropView(stmt) => write!(f, "{stmt}")?,
+            Statement::ShowViews(stmt) => write!(f, "{stmt}")?,
+            Statement::DescribeView(stmt) => write!(f, "{stmt}")?,
             Statement::CreateStream(stmt) => write!(f, "{stmt}")?,
             Statement::DropStream(stmt) => write!(f, "{stmt}")?,
             Statement::ShowStreams(stmt) => write!(f, "{stmt}")?,

src/query/ast/src/ast/statements/view.rs

@@ -23,6 +23,7 @@ use crate::ast::write_comma_separated_list;
 use crate::ast::write_dot_separated_list;
 use crate::ast::Identifier;
 use crate::ast::Query;
+use crate::ast::ShowLimit;
 
 #[derive(Debug, Clone, PartialEq, Drive, DriveMut)]
 pub struct CreateViewStmt {
@@ -113,3 +114,58 @@ impl Display for DropViewStmt {
         )
     }
 }
+
+#[derive(Debug, Clone, PartialEq, Drive, DriveMut)]
+pub struct ShowViewsStmt {
+    pub catalog: Option<Identifier>,
+    pub database: Option<Identifier>,
+    #[drive(skip)]
+    pub full: bool,
+    pub limit: Option<ShowLimit>,
+    #[drive(skip)]
+    pub with_history: bool,
+}
+
+impl Display for ShowViewsStmt {
+    fn fmt(&self, f: &mut Formatter) -> std::fmt::Result {
+        write!(f, "SHOW")?;
+        if self.full {
+            write!(f, " FULL")?;
+        }
+        write!(f, " VIEWS")?;
+        if self.with_history {
+            write!(f, " HISTORY")?;
+        }
+        if let Some(database) = &self.database {
+            write!(f, " FROM ")?;
+            if let Some(catalog) = &self.catalog {
+                write!(f, "{catalog}.",)?;
+            }
+            write!(f, "{database}")?;
+        }
+        if let Some(limit) = &self.limit {
+            write!(f, " {limit}")?;
+        }
+
+        Ok(())
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Drive, DriveMut)]
+pub struct DescribeViewStmt {
+    pub catalog: Option<Identifier>,
+    pub database: Option<Identifier>,
+    pub view: Identifier,
+}
+
+impl Display for DescribeViewStmt {
+    fn fmt(&self, f: &mut Formatter) -> std::fmt::Result {
+        write!(f, "DESCRIBE ")?;
+        write_dot_separated_list(
+            f,
+            self.catalog
+                .iter()
+                .chain(self.database.iter().chain(Some(&self.view))),
+        )
+    }
+}

src/query/ast/src/ast/visitors/visitor.rs

@@ -572,6 +572,10 @@ pub trait Visitor<'ast>: Sized {
 
     fn visit_drop_view(&mut self, _stmt: &'ast DropViewStmt) {}
 
+    fn visit_show_views(&mut self, _stmt: &'ast ShowViewsStmt) {}
+
+    fn visit_describe_view(&mut self, _stmt: &'ast DescribeViewStmt) {}
+
     fn visit_create_stream(&mut self, _stmt: &'ast CreateStreamStmt) {}
 
     fn visit_drop_stream(&mut self, _stmt: &'ast DropStreamStmt) {}

src/query/ast/src/ast/visitors/visitor_mut.rs

@@ -585,6 +585,10 @@ pub trait VisitorMut: Sized {
 
     fn visit_drop_view(&mut self, _stmt: &mut DropViewStmt) {}
 
+    fn visit_show_views(&mut self, _stmt: &mut ShowViewsStmt) {}
+
+    fn visit_describe_view(&mut self, _stmt: &mut DescribeViewStmt) {}
+
     fn visit_create_stream(&mut self, _stmt: &mut CreateStreamStmt) {}
 
     fn visit_drop_stream(&mut self, _stmt: &mut DropStreamStmt) {}

src/query/ast/src/ast/visitors/walk.rs

@@ -451,6 +451,8 @@ pub fn walk_statement<'a, V: Visitor<'a>>(visitor: &mut V, statement: &'a Statem
         Statement::CreateView(stmt) => visitor.visit_create_view(stmt),
         Statement::AlterView(stmt) => visitor.visit_alter_view(stmt),
         Statement::DropView(stmt) => visitor.visit_drop_view(stmt),
+        Statement::ShowViews(stmt) => visitor.visit_show_views(stmt),
+        Statement::DescribeView(stmt) => visitor.visit_describe_view(stmt),
         Statement::CreateStream(stmt) => visitor.visit_create_stream(stmt),
         Statement::DropStream(stmt) => visitor.visit_drop_stream(stmt),
         Statement::ShowStreams(stmt) => visitor.visit_show_streams(stmt),

src/query/ast/src/ast/visitors/walk_mut.rs

@@ -446,6 +446,8 @@ pub fn walk_statement_mut<V: VisitorMut>(visitor: &mut V, statement: &mut Statem
         Statement::CreateView(stmt) => visitor.visit_create_view(stmt),
         Statement::AlterView(stmt) => visitor.visit_alter_view(stmt),
         Statement::DropView(stmt) => visitor.visit_drop_view(stmt),
+        Statement::ShowViews(stmt) => visitor.visit_show_views(stmt),
+        Statement::DescribeView(stmt) => visitor.visit_describe_view(stmt),
         Statement::CreateStream(stmt) => visitor.visit_create_stream(stmt),
         Statement::DropStream(stmt) => visitor.visit_drop_stream(stmt),
         Statement::ShowStreams(stmt) => visitor.visit_show_streams(stmt),

src/query/ast/src/parser/statement.rs

@@ -918,6 +918,37 @@ pub fn statement_body(i: Input) -> IResult<Statement> {
             })
         },
     );
+    let show_views = map(
+        rule! {
+            SHOW ~ FULL? ~ VIEWS ~ HISTORY? ~ ( ( FROM | IN ) ~ #dot_separated_idents_1_to_2 )? ~ #show_limit?
+        },
+        |(_, opt_full, _, opt_history, ctl_db, limit)| {
+            let (catalog, database) = match ctl_db {
+                Some((_, (Some(c), d))) => (Some(c), Some(d)),
+                Some((_, (None, d))) => (None, Some(d)),
+                _ => (None, None),
+            };
+            Statement::ShowViews(ShowViewsStmt {
+                catalog,
+                database,
+                full: opt_full.is_some(),
+                limit,
+                with_history: opt_history.is_some(),
+            })
+        },
+    );
+    let describe_view = map(
+        rule! {
+            ( DESC | DESCRIBE ) ~ VIEW ~ #dot_separated_idents_1_to_3
+        },
+        |(_, _, (catalog, database, view))| {
+            Statement::DescribeView(DescribeViewStmt {
+                catalog,
+                database,
+                view,
+            })
+        },
+    );
 
     let create_index = map_res(
         rule! {
@@ -2048,6 +2079,7 @@ pub fn statement_body(i: Input) -> IResult<Statement> {
             #show_tables : "`SHOW [FULL] TABLES [FROM <database>] [<show_limit>]`"
             | #show_columns : "`SHOW [FULL] COLUMNS FROM <table> [FROM|IN <catalog>.<database>] [<show_limit>]`"
             | #show_create_table : "`SHOW CREATE TABLE [<database>.]<table>`"
+            | #describe_view : "`DESCRIBE VIEW [<database>.]<view>`"
             | #describe_table : "`DESCRIBE [<database>.]<table>`"
             | #show_fields : "`SHOW FIELDS FROM [<database>.]<table>`"
             | #show_tables_status : "`SHOW TABLES STATUS [FROM <database>] [<show_limit>]`"
@@ -2071,6 +2103,7 @@ pub fn statement_body(i: Input) -> IResult<Statement> {
             #create_view : "`CREATE [OR REPLACE] VIEW [IF NOT EXISTS] [<database>.]<view> [(<column>, ...)] AS SELECT ...`"
             | #drop_view : "`DROP VIEW [IF EXISTS] [<database>.]<view>`"
             | #alter_view : "`ALTER VIEW [<database>.]<view> [(<column>, ...)] AS SELECT ...`"
+            | #show_views : "`SHOW [FULL] VIEWS [FROM <database>] [<show_limit>]`"
             | #stream_table
             | #create_index: "`CREATE [OR REPLACE] AGGREGATING INDEX [IF NOT EXISTS] <index> AS SELECT ...`"
             | #drop_index: "`DROP <index_type> INDEX [IF EXISTS] <index>`"

src/query/ast/src/parser/token.rs

@@ -1109,6 +1109,8 @@ pub enum TokenKind {
     VERBOSE,
     #[token("VIEW", ignore(ascii_case))]
     VIEW,
+    #[token("VIEWS", ignore(ascii_case))]
+    VIEWS,
     #[token("VIRTUAL", ignore(ascii_case))]
     VIRTUAL,
     #[token("WHEN", ignore(ascii_case))]

src/query/ast/tests/it/parser.rs

@@ -142,6 +142,11 @@ fn test_statement() {
         r#"create view v1(c1) as select number % 3 as a from numbers(1000);"#,
         r#"create or replace view v1(c1) as select number % 3 as a from numbers(1000);"#,
         r#"alter view v1(c2) as select number % 3 as a from numbers(1000);"#,
+        r#"show views"#,
+        r#"show views format TabSeparatedWithNamesAndTypes;"#,
+        r#"show full views"#,
+        r#"show full views from db"#,
+        r#"show full views from ctl.db"#,
         r#"create stream test2.s1 on table test.t append_only = false;"#,
         r#"create stream if not exists test2.s2 on table test.t at (stream => test1.s1) comment = 'this is a stream';"#,
         r#"create or replace stream test2.s1 on table test.t append_only = false;"#,